Matilda Nicholas, MD, PhD

To the Editor:

Miliarial gout is a rare intradermal manifestation of tophaceous gout. It was first described in 2007 when a patient presented with multiple small papules with a red base containing a white- to cream-colored substance,¹ which has rarely been reported,^1-6 according to a PubMed search of articles indexed for MEDLINE from 2007 to 2023 using the term miliarial gout. We describe a case of miliarial gout in a patient with a history of gout, uric acid levels within reference range, and immunocompromised status due to a prior orthotopic heart transplant.

A 59-year-old man presented with innumerable subcutaneous, firm, popcornlike clustered papules on the posterior surfaces of the upper arms and thighs of 5 years’ duration (Figure 1). The involved areas were sometimes painful on manipulation, but the patient was otherwise asymptomatic. His medical history was notable for tophaceous gout of more than 10 years’ duration, calcinosis cutis, adrenal insufficiency, essential hypertension, and an orthotopic heart transplant 2 years prior to the current presentation. At the current presentation he was taking tacrolimus, colchicine, febuxostat, and low-dose prednisone. The patient denied any other skin changes such as ulceration or bullae. In addition to the innumerable subcutaneous papules, he had much larger firm deep nodules bilaterally on the elbow (Figure 2). A complete blood cell count with differential and comprehensive metabolic panel results were within reference range. A 4-mm punch biopsy of the right posterior arm revealed dermal deposits consistent with gout on hematoxylin and eosin staining (Figure 3) but no calcium deposits on von Kossa staining, consistent with miliarial gout.

He was treated with 0.6 mg of colchicine daily, 80 mg of febuxostat twice daily, and 2.5 mg of prednisone daily. Unfortunately, the patient had difficulty affording his medications and therefore experienced frequent flares.

Gout is caused by inflammation that occurs from deposition of monosodium urate crystals in tissues, most commonly occurring in the skin and joints. Gout affects8.3 million individuals and is one of the most common rheumatic diseases of adulthood. The classic presentation of the acute form is monoarticular with associated swelling, erythema, and pain. The chronic form (also known as tophaceous gout) affects soft tissue and presents with smooth or multilobulated nodules.² Miliarial gout is a rare variant of chronic tophaceous gout, and the diagnosis is based on atypical location, size, and distribution of tophi deposition.

In the updated American College of Rheumatology criteria for gout published in 2020, tophi are defined as draining or chalklike subcutaneous nodules that typically are located in joints, ears, olecranon bursae, finger pads, and tendons.³ The term miliarial gout, which is not universally defined, is used to describe the morphology and distribution of tophi deposition in areas outside of the typical locations defined by the American College of Rheumatology criteria. Miliarial refers to the small, multilobulated, and disseminated presentation of tophi. The involvement of atypical locations distinguishes miliarial gout from chronic tophaceous gout.

The cause of tophi deposition in atypical locations is unknown. It is thought that patients with a history of sustained hyperuricemia have a much greater burden of urate crystal deposition, which can lead to involvement of atypical locations. Our patient had innumerable, discrete, 1- to 5-mm, multilobulated tophi located on the posterior upper arms and thighs even though his uric acid levels were within reference range over the last 5 years.

Miliarial gout is a rare entity.¹ In 2007, Shukla et al¹ coined the term miliarial gout when reporting the first known presentation of a patient with multiple tiny papules containing a white or creamlike substance scattered on an erythematous base. Other cases of miliarial gout have commonly involved the metacarpophalangeal joints of the hands, knees, abdomen, extensor forearms, and thighs.⁵ Similarly, our patient had disease involvement of the posterior upper arms and thighs. Furthermore, miliarial gout has been associated with carpal tunnel syndrome; monosodium urate crystal deposition in this space can lead to a clinical diagnosis of this condition.⁶

With a history of orthotopic heart transplant, it is possible that our patient’s immunocompromised status could have increased his susceptibility for the miliarial form of chronic tophaceous gout. Gout reportedly is the most common inflammatory arthritis in transplant recipients, with the highest prevalence following renal and heart transplantation.⁷ Pretransplant hyperuricemia is correlated with higher probabilities of posttransplant gout.⁸ In patients with a heart transplant, hyperuricemia may be due to diuretic use. Additionally, the presence of a gout diagnosis before transplant nearly triples the likelihood of posttransplant gout, which often is more severe than de novo gout, as seen in our patient. Calcineurin inhibitors, including tacrolimus, also can predispose patients to hyperuricemia and more severe forms of gout in the posttransplant phase by limiting fractional urate excretion within the first 3 months of therapy.⁷ Treatment with oral steroids, as in our patient, also has been identified as a potential inciting factor for the development of cutaneous tophaceous gout.⁹

Treatment with allopurinol and colchicine has been effective in patients with miliarial gout. Obesity and long-term treatment with furosemide (which our patient was not taking) are considered risk factors for the deposition of dermal and hypodermal urates.⁹ Our patient had a body mass index of 35 (≥30 indicates obesity); therefore, he also should be counseled on lifestyle modifications for optimal disease control.

To the Editor:

Miliarial gout is a rare intradermal manifestation of tophaceous gout. It was first described in 2007 when a patient presented with multiple small papules with a red base containing a white- to cream-colored substance,¹ which has rarely been reported,^1-6 according to a PubMed search of articles indexed for MEDLINE from 2007 to 2023 using the term miliarial gout. We describe a case of miliarial gout in a patient with a history of gout, uric acid levels within reference range, and immunocompromised status due to a prior orthotopic heart transplant.

A 59-year-old man presented with innumerable subcutaneous, firm, popcornlike clustered papules on the posterior surfaces of the upper arms and thighs of 5 years’ duration (Figure 1). The involved areas were sometimes painful on manipulation, but the patient was otherwise asymptomatic. His medical history was notable for tophaceous gout of more than 10 years’ duration, calcinosis cutis, adrenal insufficiency, essential hypertension, and an orthotopic heart transplant 2 years prior to the current presentation. At the current presentation he was taking tacrolimus, colchicine, febuxostat, and low-dose prednisone. The patient denied any other skin changes such as ulceration or bullae. In addition to the innumerable subcutaneous papules, he had much larger firm deep nodules bilaterally on the elbow (Figure 2). A complete blood cell count with differential and comprehensive metabolic panel results were within reference range. A 4-mm punch biopsy of the right posterior arm revealed dermal deposits consistent with gout on hematoxylin and eosin staining (Figure 3) but no calcium deposits on von Kossa staining, consistent with miliarial gout.

He was treated with 0.6 mg of colchicine daily, 80 mg of febuxostat twice daily, and 2.5 mg of prednisone daily. Unfortunately, the patient had difficulty affording his medications and therefore experienced frequent flares.

Gout is caused by inflammation that occurs from deposition of monosodium urate crystals in tissues, most commonly occurring in the skin and joints. Gout affects8.3 million individuals and is one of the most common rheumatic diseases of adulthood. The classic presentation of the acute form is monoarticular with associated swelling, erythema, and pain. The chronic form (also known as tophaceous gout) affects soft tissue and presents with smooth or multilobulated nodules.² Miliarial gout is a rare variant of chronic tophaceous gout, and the diagnosis is based on atypical location, size, and distribution of tophi deposition.

In the updated American College of Rheumatology criteria for gout published in 2020, tophi are defined as draining or chalklike subcutaneous nodules that typically are located in joints, ears, olecranon bursae, finger pads, and tendons.³ The term miliarial gout, which is not universally defined, is used to describe the morphology and distribution of tophi deposition in areas outside of the typical locations defined by the American College of Rheumatology criteria. Miliarial refers to the small, multilobulated, and disseminated presentation of tophi. The involvement of atypical locations distinguishes miliarial gout from chronic tophaceous gout.

The cause of tophi deposition in atypical locations is unknown. It is thought that patients with a history of sustained hyperuricemia have a much greater burden of urate crystal deposition, which can lead to involvement of atypical locations. Our patient had innumerable, discrete, 1- to 5-mm, multilobulated tophi located on the posterior upper arms and thighs even though his uric acid levels were within reference range over the last 5 years.

Miliarial gout is a rare entity.¹ In 2007, Shukla et al¹ coined the term miliarial gout when reporting the first known presentation of a patient with multiple tiny papules containing a white or creamlike substance scattered on an erythematous base. Other cases of miliarial gout have commonly involved the metacarpophalangeal joints of the hands, knees, abdomen, extensor forearms, and thighs.⁵ Similarly, our patient had disease involvement of the posterior upper arms and thighs. Furthermore, miliarial gout has been associated with carpal tunnel syndrome; monosodium urate crystal deposition in this space can lead to a clinical diagnosis of this condition.⁶

With a history of orthotopic heart transplant, it is possible that our patient’s immunocompromised status could have increased his susceptibility for the miliarial form of chronic tophaceous gout. Gout reportedly is the most common inflammatory arthritis in transplant recipients, with the highest prevalence following renal and heart transplantation.⁷ Pretransplant hyperuricemia is correlated with higher probabilities of posttransplant gout.⁸ In patients with a heart transplant, hyperuricemia may be due to diuretic use. Additionally, the presence of a gout diagnosis before transplant nearly triples the likelihood of posttransplant gout, which often is more severe than de novo gout, as seen in our patient. Calcineurin inhibitors, including tacrolimus, also can predispose patients to hyperuricemia and more severe forms of gout in the posttransplant phase by limiting fractional urate excretion within the first 3 months of therapy.⁷ Treatment with oral steroids, as in our patient, also has been identified as a potential inciting factor for the development of cutaneous tophaceous gout.⁹

Treatment with allopurinol and colchicine has been effective in patients with miliarial gout. Obesity and long-term treatment with furosemide (which our patient was not taking) are considered risk factors for the deposition of dermal and hypodermal urates.⁹ Our patient had a body mass index of 35 (≥30 indicates obesity); therefore, he also should be counseled on lifestyle modifications for optimal disease control.

To the Editor:

Miliarial gout is a rare intradermal manifestation of tophaceous gout. It was first described in 2007 when a patient presented with multiple small papules with a red base containing a white- to cream-colored substance,¹ which has rarely been reported,^1-6 according to a PubMed search of articles indexed for MEDLINE from 2007 to 2023 using the term miliarial gout. We describe a case of miliarial gout in a patient with a history of gout, uric acid levels within reference range, and immunocompromised status due to a prior orthotopic heart transplant.

A 59-year-old man presented with innumerable subcutaneous, firm, popcornlike clustered papules on the posterior surfaces of the upper arms and thighs of 5 years’ duration (Figure 1). The involved areas were sometimes painful on manipulation, but the patient was otherwise asymptomatic. His medical history was notable for tophaceous gout of more than 10 years’ duration, calcinosis cutis, adrenal insufficiency, essential hypertension, and an orthotopic heart transplant 2 years prior to the current presentation. At the current presentation he was taking tacrolimus, colchicine, febuxostat, and low-dose prednisone. The patient denied any other skin changes such as ulceration or bullae. In addition to the innumerable subcutaneous papules, he had much larger firm deep nodules bilaterally on the elbow (Figure 2). A complete blood cell count with differential and comprehensive metabolic panel results were within reference range. A 4-mm punch biopsy of the right posterior arm revealed dermal deposits consistent with gout on hematoxylin and eosin staining (Figure 3) but no calcium deposits on von Kossa staining, consistent with miliarial gout.

He was treated with 0.6 mg of colchicine daily, 80 mg of febuxostat twice daily, and 2.5 mg of prednisone daily. Unfortunately, the patient had difficulty affording his medications and therefore experienced frequent flares.

Gout is caused by inflammation that occurs from deposition of monosodium urate crystals in tissues, most commonly occurring in the skin and joints. Gout affects8.3 million individuals and is one of the most common rheumatic diseases of adulthood. The classic presentation of the acute form is monoarticular with associated swelling, erythema, and pain. The chronic form (also known as tophaceous gout) affects soft tissue and presents with smooth or multilobulated nodules.² Miliarial gout is a rare variant of chronic tophaceous gout, and the diagnosis is based on atypical location, size, and distribution of tophi deposition.

In the updated American College of Rheumatology criteria for gout published in 2020, tophi are defined as draining or chalklike subcutaneous nodules that typically are located in joints, ears, olecranon bursae, finger pads, and tendons.³ The term miliarial gout, which is not universally defined, is used to describe the morphology and distribution of tophi deposition in areas outside of the typical locations defined by the American College of Rheumatology criteria. Miliarial refers to the small, multilobulated, and disseminated presentation of tophi. The involvement of atypical locations distinguishes miliarial gout from chronic tophaceous gout.

The cause of tophi deposition in atypical locations is unknown. It is thought that patients with a history of sustained hyperuricemia have a much greater burden of urate crystal deposition, which can lead to involvement of atypical locations. Our patient had innumerable, discrete, 1- to 5-mm, multilobulated tophi located on the posterior upper arms and thighs even though his uric acid levels were within reference range over the last 5 years.

Miliarial gout is a rare entity.¹ In 2007, Shukla et al¹ coined the term miliarial gout when reporting the first known presentation of a patient with multiple tiny papules containing a white or creamlike substance scattered on an erythematous base. Other cases of miliarial gout have commonly involved the metacarpophalangeal joints of the hands, knees, abdomen, extensor forearms, and thighs.⁵ Similarly, our patient had disease involvement of the posterior upper arms and thighs. Furthermore, miliarial gout has been associated with carpal tunnel syndrome; monosodium urate crystal deposition in this space can lead to a clinical diagnosis of this condition.⁶

With a history of orthotopic heart transplant, it is possible that our patient’s immunocompromised status could have increased his susceptibility for the miliarial form of chronic tophaceous gout. Gout reportedly is the most common inflammatory arthritis in transplant recipients, with the highest prevalence following renal and heart transplantation.⁷ Pretransplant hyperuricemia is correlated with higher probabilities of posttransplant gout.⁸ In patients with a heart transplant, hyperuricemia may be due to diuretic use. Additionally, the presence of a gout diagnosis before transplant nearly triples the likelihood of posttransplant gout, which often is more severe than de novo gout, as seen in our patient. Calcineurin inhibitors, including tacrolimus, also can predispose patients to hyperuricemia and more severe forms of gout in the posttransplant phase by limiting fractional urate excretion within the first 3 months of therapy.⁷ Treatment with oral steroids, as in our patient, also has been identified as a potential inciting factor for the development of cutaneous tophaceous gout.⁹

Treatment with allopurinol and colchicine has been effective in patients with miliarial gout. Obesity and long-term treatment with furosemide (which our patient was not taking) are considered risk factors for the deposition of dermal and hypodermal urates.⁹ Our patient had a body mass index of 35 (≥30 indicates obesity); therefore, he also should be counseled on lifestyle modifications for optimal disease control.

The ideal method of resident education is a subject of great interest within the medical community, and many dermatology residency programs utilize a traditional classroom model for didactic training consisting of required textbook reading completed at home and classroom lectures that often include presentations featuring text, dermatology images, and questions throughout the lecture. A second teaching model is known as the flipped, or inverted, classroom. This model moves the didactic material that typically is covered in the classroom into the realm of home study or homework and focuses on application and clarification of the new material in the classroom. ¹ There is an emphasis on completing and understanding course material prior to the classroom session. Students are expected to be prepared for the lesson, and the classroom session can include question review and deeper exploration of the topic with a focus on subject mastery. ²

In recent years, the flipped classroom model has been used in elementary education, due in part to the influence of teachers Bergmann and Sams,³ as described in their book Flip Your Classroom: Reach Every Student in Every Class Every Day. More recently, Prober and Khan⁴ argued for its use in medical education, and this model has been utilized in medical school curricula to teach specialty subjects, including medical dermatology.⁵

Given the increasing popularity and use of the flipped classroom, the primary objective of this study was to determine if a difference in knowledge acquisition and resident perception exists between the traditional and flipped classrooms. If differences do exist, the secondary aim was to quantify them. We hypothesized that the flipped classroom actively engages residents and would improve both knowledge acquisition and resident sentiment toward the residency program curriculum compared to the traditional model.

Methods

The Duke Health (Durham, North Carolina) institutional review board granted approval for this study. All of the dermatology residents from Duke University Medical Center for the 2014-2015 academic year participated in this study. Twelve individual lectures chosen by the dermatology residency program director were included: 6 traditional lectures and 6 flipped lectures. The lectures were paired for similar content.

Survey Administration
Each resident was assigned a unique 4-digit numeric code that was unknown to the investigators and recorded at the beginning of each survey. The residents expected flipped lectures for each session and were blinded as to when a traditional lecture and quiz would occur, with the exception of the resident providing the lecture. Classroom presentations were immediately followed by a voluntary survey administered through Qualtrics.⁶ Consent was given at the beginning of each survey, followed by 10 factual questions and 10 perception questions. The factual questions varied based on the lecture topic and were multiple-choice questions written by the program director, associate program director, and faculty. Each factual question was worth 10 points, and the scaled score for each quiz had a maximum value of 100. The perception questions were developed by the authors (J.H. and A.R.A.) in consultation with a survey methodology expert at the Duke Social Science Research Institute. These questions remained constant across each survey and were descriptive based on standard response scales. The data were extracted from Qualtrics for statistical analysis.

Statistical Analysis
The mean score with the standard deviation for each factual question quiz was calculated and plotted. A generalized linear mixed model was created to study the difference in quiz scores between the 2 classroom models after adjusting for other covariates, including resident, the interaction between resident and class type, quiz time, and the interaction between class type and quiz time. The variable resident was specified as a random variable, and a variance components covariance structure was used. For the perception questions, the frequency and percentage of each answer for a question was counted. Generalized linear mixed models with a Poisson distribution were created to study the difference in answers for each survey question between the 2 curriculum types after adjusting for other covariates, including scores for factual questions, quiz time, and the interaction between class type and quiz time. The variable resident was again specified as a random variable, and a diagonal covariance structure was used. All statistical analyses were carried out using SAS software package version 9.4 (SAS Institute) by the Duke University Department of Biostatistics and Bioinformatics. P<.05 was considered statistically significant.

Results

All 9 of the department’s residents were included and participated in this study. Mean score with standard deviation for each factual quiz is plotted in the Figure. Across all residents, the mean factual quiz score was slightly higher but not statistically significant in the flipped vs traditional classrooms (67.5% vs 65.4%; P=.448)(data not shown). When comparing traditional and flipped factual quiz scores by individual resident, there was not a significant difference in quiz performance (P=.166)(data not shown). However, there was a significant difference in the factual quiz scores among residents for all quizzes (P=.005) as well as a significant difference in performance between each individual quiz over time (P<.001)(data not shown). In the traditional classroom, residents demonstrated a trend in variable performance with each factual quiz. In the flipped classroom, residents also had variable performance, with wide-ranging scores (P=.008)(data not shown).

Each resident also answered 10 perception questions (Table 1). When comparing the responses by quiz type (Table 2), there was a significant difference for several questions in favor of the flipped classroom: how actively residents thought their co-residents participated in the lecture (P<.001), how much each resident enjoyed the session (P=.038), and how much each resident believed their co-residents enjoyed the session (P=.026). Additionally, residents thought that the flipped classroom sessions were more efficient (P=.033), better prepared them for boards (P=.050), and better prepared them for clinical practice (P=.034). There was not a significant difference in the amount of reading and preparation residents did for class (P=.697), how actively the residents thought they participated in the lecture (P=.303), the effectiveness of the day’s curriculum structure (P=.178), or whether residents thought the lesson increased their knowledge on the topic (P=.084).

Comment

The traditional model in medical education has undergone changes in recent years, and researchers have been looking for new ways to convey more information in shorter periods of time, especially as the field of medicine continues to expand. Despite the growing popularity and adoption of the flipped classroom, studies in dermatology have been limited. In this study, we compared a traditional classroom model with the flipped model, assessing both knowledge acquisition and resident perception of the experience.

There was not a significant difference in mean objective quiz scores when comparing the 2 curricula. The flipped model was not better or worse than the traditional teaching model at relaying information and promoting learning. Rather, there was a significant difference in quiz scores based on the individual resident and on the individual quiz. Individual performance was not affected by the teaching model but rather by the individual resident and lecture topic.

These findings differ from a study of internal medicine residents, which revealed that trainees in a quality-improvement flipped classroom had greater increases in knowledge than a traditional cohort.⁷ It is difficult to make direct comparisons to this group, given the difference in specialty and subject content. In comparison, an emergency medicine program completed a cross-sectional cohort study of in-service examination scores in the setting of a traditional curriculum (2011-2012) vs a flipped curriculum (2015-2016) and found that there was no statistical difference in average in-service examination scores.⁸ The type of examination content in this study may be more similar to the quizzes that our residents experienced (ie, fact-based material based on traditional medical knowledge).

The dermatology residents favored the flipped curriculum for 6 of 10 perception questions, which included areas of co-resident participation, personal and co-resident enjoyment, efficiency, boards preparation, and preparation for clinical practice. They did not favor the flipped classroom for prelecture preparation, personal participation, lecture effectiveness, or knowledge acquisition. They perceived their peers as being more engaged and found the flipped classroom to be a more positive experience. The residents thought that the flipped lectures were more time efficient, which could have contributed to overall learner satisfaction. Additionally, they thought that the flipped model better prepared them for both the boards and clinical practice, which are markers of future performance.

These findings are consistent with other studies that revealed improved postcourse perception scores for a quality improvement emergency medicine–flipped classroom. Most of this group preferred the flipped classroom over the traditional after completion of the flipped curriculum.⁹ A neurosurgery residency program also reported increased resident engagement and resident preference for a newly designed flipped curriculum.¹⁰

Overall, our data indicate that there was no objective change in knowledge acquisition at the time of the quiz, but learner satisfaction was significantly greater in the flipped classroom model.

Limitations
This study was comprised of a small number of residents from a single institution and was based on a limited number of lectures given throughout the year. All lectures during the study year were flipped with the exception of the 6 traditional study lectures. Therefore, each resident who presented a traditional lecture was not blinded for her individual assigned lecture. In addition, because traditional lectures only occurred on study days, once the lectures started, all trainees could predict that a content quiz would occur at the end of the session, which could potentially introduce bias toward better quiz performance for the traditional lectures.

Conclusion

When comparing traditional and flipped classroom models, we found no difference in knowledge acquisition. Rather, the difference in quiz scores was among individual residents. There was a significant positive difference in how residents perceived these teaching models, including enjoyment and feeling prepared for the boards. The flipped classroom model provides another opportunity to better engage residents during teaching and should be considered as part of dermatology residency education.



Acknowledgments
Duke Social Sciences Institute postdoctoral fellow Scott Clifford, PhD, and Duke Dermatology residents Daniel Chang, MD; Sinae Kane, MD; Rebecca Bialas, MD; Jolene Jewell, MD; Elizabeth Ju, MD; Michael Raisch, MD; Reed Garza, MD; Joanna Hooten, MD; and E. Schell Bressler, MD (all Durham, North Carolina).

The ideal method of resident education is a subject of great interest within the medical community, and many dermatology residency programs utilize a traditional classroom model for didactic training consisting of required textbook reading completed at home and classroom lectures that often include presentations featuring text, dermatology images, and questions throughout the lecture. A second teaching model is known as the flipped, or inverted, classroom. This model moves the didactic material that typically is covered in the classroom into the realm of home study or homework and focuses on application and clarification of the new material in the classroom. ¹ There is an emphasis on completing and understanding course material prior to the classroom session. Students are expected to be prepared for the lesson, and the classroom session can include question review and deeper exploration of the topic with a focus on subject mastery. ²

In recent years, the flipped classroom model has been used in elementary education, due in part to the influence of teachers Bergmann and Sams,³ as described in their book Flip Your Classroom: Reach Every Student in Every Class Every Day. More recently, Prober and Khan⁴ argued for its use in medical education, and this model has been utilized in medical school curricula to teach specialty subjects, including medical dermatology.⁵

Given the increasing popularity and use of the flipped classroom, the primary objective of this study was to determine if a difference in knowledge acquisition and resident perception exists between the traditional and flipped classrooms. If differences do exist, the secondary aim was to quantify them. We hypothesized that the flipped classroom actively engages residents and would improve both knowledge acquisition and resident sentiment toward the residency program curriculum compared to the traditional model.

Methods

The Duke Health (Durham, North Carolina) institutional review board granted approval for this study. All of the dermatology residents from Duke University Medical Center for the 2014-2015 academic year participated in this study. Twelve individual lectures chosen by the dermatology residency program director were included: 6 traditional lectures and 6 flipped lectures. The lectures were paired for similar content.

Survey Administration
Each resident was assigned a unique 4-digit numeric code that was unknown to the investigators and recorded at the beginning of each survey. The residents expected flipped lectures for each session and were blinded as to when a traditional lecture and quiz would occur, with the exception of the resident providing the lecture. Classroom presentations were immediately followed by a voluntary survey administered through Qualtrics.⁶ Consent was given at the beginning of each survey, followed by 10 factual questions and 10 perception questions. The factual questions varied based on the lecture topic and were multiple-choice questions written by the program director, associate program director, and faculty. Each factual question was worth 10 points, and the scaled score for each quiz had a maximum value of 100. The perception questions were developed by the authors (J.H. and A.R.A.) in consultation with a survey methodology expert at the Duke Social Science Research Institute. These questions remained constant across each survey and were descriptive based on standard response scales. The data were extracted from Qualtrics for statistical analysis.

Statistical Analysis
The mean score with the standard deviation for each factual question quiz was calculated and plotted. A generalized linear mixed model was created to study the difference in quiz scores between the 2 classroom models after adjusting for other covariates, including resident, the interaction between resident and class type, quiz time, and the interaction between class type and quiz time. The variable resident was specified as a random variable, and a variance components covariance structure was used. For the perception questions, the frequency and percentage of each answer for a question was counted. Generalized linear mixed models with a Poisson distribution were created to study the difference in answers for each survey question between the 2 curriculum types after adjusting for other covariates, including scores for factual questions, quiz time, and the interaction between class type and quiz time. The variable resident was again specified as a random variable, and a diagonal covariance structure was used. All statistical analyses were carried out using SAS software package version 9.4 (SAS Institute) by the Duke University Department of Biostatistics and Bioinformatics. P<.05 was considered statistically significant.

Results

All 9 of the department’s residents were included and participated in this study. Mean score with standard deviation for each factual quiz is plotted in the Figure. Across all residents, the mean factual quiz score was slightly higher but not statistically significant in the flipped vs traditional classrooms (67.5% vs 65.4%; P=.448)(data not shown). When comparing traditional and flipped factual quiz scores by individual resident, there was not a significant difference in quiz performance (P=.166)(data not shown). However, there was a significant difference in the factual quiz scores among residents for all quizzes (P=.005) as well as a significant difference in performance between each individual quiz over time (P<.001)(data not shown). In the traditional classroom, residents demonstrated a trend in variable performance with each factual quiz. In the flipped classroom, residents also had variable performance, with wide-ranging scores (P=.008)(data not shown).

Each resident also answered 10 perception questions (Table 1). When comparing the responses by quiz type (Table 2), there was a significant difference for several questions in favor of the flipped classroom: how actively residents thought their co-residents participated in the lecture (P<.001), how much each resident enjoyed the session (P=.038), and how much each resident believed their co-residents enjoyed the session (P=.026). Additionally, residents thought that the flipped classroom sessions were more efficient (P=.033), better prepared them for boards (P=.050), and better prepared them for clinical practice (P=.034). There was not a significant difference in the amount of reading and preparation residents did for class (P=.697), how actively the residents thought they participated in the lecture (P=.303), the effectiveness of the day’s curriculum structure (P=.178), or whether residents thought the lesson increased their knowledge on the topic (P=.084).

Comment

The traditional model in medical education has undergone changes in recent years, and researchers have been looking for new ways to convey more information in shorter periods of time, especially as the field of medicine continues to expand. Despite the growing popularity and adoption of the flipped classroom, studies in dermatology have been limited. In this study, we compared a traditional classroom model with the flipped model, assessing both knowledge acquisition and resident perception of the experience.

There was not a significant difference in mean objective quiz scores when comparing the 2 curricula. The flipped model was not better or worse than the traditional teaching model at relaying information and promoting learning. Rather, there was a significant difference in quiz scores based on the individual resident and on the individual quiz. Individual performance was not affected by the teaching model but rather by the individual resident and lecture topic.

These findings differ from a study of internal medicine residents, which revealed that trainees in a quality-improvement flipped classroom had greater increases in knowledge than a traditional cohort.⁷ It is difficult to make direct comparisons to this group, given the difference in specialty and subject content. In comparison, an emergency medicine program completed a cross-sectional cohort study of in-service examination scores in the setting of a traditional curriculum (2011-2012) vs a flipped curriculum (2015-2016) and found that there was no statistical difference in average in-service examination scores.⁸ The type of examination content in this study may be more similar to the quizzes that our residents experienced (ie, fact-based material based on traditional medical knowledge).

The dermatology residents favored the flipped curriculum for 6 of 10 perception questions, which included areas of co-resident participation, personal and co-resident enjoyment, efficiency, boards preparation, and preparation for clinical practice. They did not favor the flipped classroom for prelecture preparation, personal participation, lecture effectiveness, or knowledge acquisition. They perceived their peers as being more engaged and found the flipped classroom to be a more positive experience. The residents thought that the flipped lectures were more time efficient, which could have contributed to overall learner satisfaction. Additionally, they thought that the flipped model better prepared them for both the boards and clinical practice, which are markers of future performance.

These findings are consistent with other studies that revealed improved postcourse perception scores for a quality improvement emergency medicine–flipped classroom. Most of this group preferred the flipped classroom over the traditional after completion of the flipped curriculum.⁹ A neurosurgery residency program also reported increased resident engagement and resident preference for a newly designed flipped curriculum.¹⁰

Overall, our data indicate that there was no objective change in knowledge acquisition at the time of the quiz, but learner satisfaction was significantly greater in the flipped classroom model.

Limitations
This study was comprised of a small number of residents from a single institution and was based on a limited number of lectures given throughout the year. All lectures during the study year were flipped with the exception of the 6 traditional study lectures. Therefore, each resident who presented a traditional lecture was not blinded for her individual assigned lecture. In addition, because traditional lectures only occurred on study days, once the lectures started, all trainees could predict that a content quiz would occur at the end of the session, which could potentially introduce bias toward better quiz performance for the traditional lectures.

Conclusion

When comparing traditional and flipped classroom models, we found no difference in knowledge acquisition. Rather, the difference in quiz scores was among individual residents. There was a significant positive difference in how residents perceived these teaching models, including enjoyment and feeling prepared for the boards. The flipped classroom model provides another opportunity to better engage residents during teaching and should be considered as part of dermatology residency education.



Acknowledgments
Duke Social Sciences Institute postdoctoral fellow Scott Clifford, PhD, and Duke Dermatology residents Daniel Chang, MD; Sinae Kane, MD; Rebecca Bialas, MD; Jolene Jewell, MD; Elizabeth Ju, MD; Michael Raisch, MD; Reed Garza, MD; Joanna Hooten, MD; and E. Schell Bressler, MD (all Durham, North Carolina).

The ideal method of resident education is a subject of great interest within the medical community, and many dermatology residency programs utilize a traditional classroom model for didactic training consisting of required textbook reading completed at home and classroom lectures that often include presentations featuring text, dermatology images, and questions throughout the lecture. A second teaching model is known as the flipped, or inverted, classroom. This model moves the didactic material that typically is covered in the classroom into the realm of home study or homework and focuses on application and clarification of the new material in the classroom. ¹ There is an emphasis on completing and understanding course material prior to the classroom session. Students are expected to be prepared for the lesson, and the classroom session can include question review and deeper exploration of the topic with a focus on subject mastery. ²

In recent years, the flipped classroom model has been used in elementary education, due in part to the influence of teachers Bergmann and Sams,³ as described in their book Flip Your Classroom: Reach Every Student in Every Class Every Day. More recently, Prober and Khan⁴ argued for its use in medical education, and this model has been utilized in medical school curricula to teach specialty subjects, including medical dermatology.⁵

Given the increasing popularity and use of the flipped classroom, the primary objective of this study was to determine if a difference in knowledge acquisition and resident perception exists between the traditional and flipped classrooms. If differences do exist, the secondary aim was to quantify them. We hypothesized that the flipped classroom actively engages residents and would improve both knowledge acquisition and resident sentiment toward the residency program curriculum compared to the traditional model.

Methods

The Duke Health (Durham, North Carolina) institutional review board granted approval for this study. All of the dermatology residents from Duke University Medical Center for the 2014-2015 academic year participated in this study. Twelve individual lectures chosen by the dermatology residency program director were included: 6 traditional lectures and 6 flipped lectures. The lectures were paired for similar content.

Survey Administration
Each resident was assigned a unique 4-digit numeric code that was unknown to the investigators and recorded at the beginning of each survey. The residents expected flipped lectures for each session and were blinded as to when a traditional lecture and quiz would occur, with the exception of the resident providing the lecture. Classroom presentations were immediately followed by a voluntary survey administered through Qualtrics.⁶ Consent was given at the beginning of each survey, followed by 10 factual questions and 10 perception questions. The factual questions varied based on the lecture topic and were multiple-choice questions written by the program director, associate program director, and faculty. Each factual question was worth 10 points, and the scaled score for each quiz had a maximum value of 100. The perception questions were developed by the authors (J.H. and A.R.A.) in consultation with a survey methodology expert at the Duke Social Science Research Institute. These questions remained constant across each survey and were descriptive based on standard response scales. The data were extracted from Qualtrics for statistical analysis.

Statistical Analysis
The mean score with the standard deviation for each factual question quiz was calculated and plotted. A generalized linear mixed model was created to study the difference in quiz scores between the 2 classroom models after adjusting for other covariates, including resident, the interaction between resident and class type, quiz time, and the interaction between class type and quiz time. The variable resident was specified as a random variable, and a variance components covariance structure was used. For the perception questions, the frequency and percentage of each answer for a question was counted. Generalized linear mixed models with a Poisson distribution were created to study the difference in answers for each survey question between the 2 curriculum types after adjusting for other covariates, including scores for factual questions, quiz time, and the interaction between class type and quiz time. The variable resident was again specified as a random variable, and a diagonal covariance structure was used. All statistical analyses were carried out using SAS software package version 9.4 (SAS Institute) by the Duke University Department of Biostatistics and Bioinformatics. P<.05 was considered statistically significant.

Results

All 9 of the department’s residents were included and participated in this study. Mean score with standard deviation for each factual quiz is plotted in the Figure. Across all residents, the mean factual quiz score was slightly higher but not statistically significant in the flipped vs traditional classrooms (67.5% vs 65.4%; P=.448)(data not shown). When comparing traditional and flipped factual quiz scores by individual resident, there was not a significant difference in quiz performance (P=.166)(data not shown). However, there was a significant difference in the factual quiz scores among residents for all quizzes (P=.005) as well as a significant difference in performance between each individual quiz over time (P<.001)(data not shown). In the traditional classroom, residents demonstrated a trend in variable performance with each factual quiz. In the flipped classroom, residents also had variable performance, with wide-ranging scores (P=.008)(data not shown).

Each resident also answered 10 perception questions (Table 1). When comparing the responses by quiz type (Table 2), there was a significant difference for several questions in favor of the flipped classroom: how actively residents thought their co-residents participated in the lecture (P<.001), how much each resident enjoyed the session (P=.038), and how much each resident believed their co-residents enjoyed the session (P=.026). Additionally, residents thought that the flipped classroom sessions were more efficient (P=.033), better prepared them for boards (P=.050), and better prepared them for clinical practice (P=.034). There was not a significant difference in the amount of reading and preparation residents did for class (P=.697), how actively the residents thought they participated in the lecture (P=.303), the effectiveness of the day’s curriculum structure (P=.178), or whether residents thought the lesson increased their knowledge on the topic (P=.084).

Comment

The traditional model in medical education has undergone changes in recent years, and researchers have been looking for new ways to convey more information in shorter periods of time, especially as the field of medicine continues to expand. Despite the growing popularity and adoption of the flipped classroom, studies in dermatology have been limited. In this study, we compared a traditional classroom model with the flipped model, assessing both knowledge acquisition and resident perception of the experience.

There was not a significant difference in mean objective quiz scores when comparing the 2 curricula. The flipped model was not better or worse than the traditional teaching model at relaying information and promoting learning. Rather, there was a significant difference in quiz scores based on the individual resident and on the individual quiz. Individual performance was not affected by the teaching model but rather by the individual resident and lecture topic.

These findings differ from a study of internal medicine residents, which revealed that trainees in a quality-improvement flipped classroom had greater increases in knowledge than a traditional cohort.⁷ It is difficult to make direct comparisons to this group, given the difference in specialty and subject content. In comparison, an emergency medicine program completed a cross-sectional cohort study of in-service examination scores in the setting of a traditional curriculum (2011-2012) vs a flipped curriculum (2015-2016) and found that there was no statistical difference in average in-service examination scores.⁸ The type of examination content in this study may be more similar to the quizzes that our residents experienced (ie, fact-based material based on traditional medical knowledge).

The dermatology residents favored the flipped curriculum for 6 of 10 perception questions, which included areas of co-resident participation, personal and co-resident enjoyment, efficiency, boards preparation, and preparation for clinical practice. They did not favor the flipped classroom for prelecture preparation, personal participation, lecture effectiveness, or knowledge acquisition. They perceived their peers as being more engaged and found the flipped classroom to be a more positive experience. The residents thought that the flipped lectures were more time efficient, which could have contributed to overall learner satisfaction. Additionally, they thought that the flipped model better prepared them for both the boards and clinical practice, which are markers of future performance.

These findings are consistent with other studies that revealed improved postcourse perception scores for a quality improvement emergency medicine–flipped classroom. Most of this group preferred the flipped classroom over the traditional after completion of the flipped curriculum.⁹ A neurosurgery residency program also reported increased resident engagement and resident preference for a newly designed flipped curriculum.¹⁰

Overall, our data indicate that there was no objective change in knowledge acquisition at the time of the quiz, but learner satisfaction was significantly greater in the flipped classroom model.

Limitations
This study was comprised of a small number of residents from a single institution and was based on a limited number of lectures given throughout the year. All lectures during the study year were flipped with the exception of the 6 traditional study lectures. Therefore, each resident who presented a traditional lecture was not blinded for her individual assigned lecture. In addition, because traditional lectures only occurred on study days, once the lectures started, all trainees could predict that a content quiz would occur at the end of the session, which could potentially introduce bias toward better quiz performance for the traditional lectures.

Conclusion

When comparing traditional and flipped classroom models, we found no difference in knowledge acquisition. Rather, the difference in quiz scores was among individual residents. There was a significant positive difference in how residents perceived these teaching models, including enjoyment and feeling prepared for the boards. The flipped classroom model provides another opportunity to better engage residents during teaching and should be considered as part of dermatology residency education.



Acknowledgments
Duke Social Sciences Institute postdoctoral fellow Scott Clifford, PhD, and Duke Dermatology residents Daniel Chang, MD; Sinae Kane, MD; Rebecca Bialas, MD; Jolene Jewell, MD; Elizabeth Ju, MD; Michael Raisch, MD; Reed Garza, MD; Joanna Hooten, MD; and E. Schell Bressler, MD (all Durham, North Carolina).