The prevalence of acne in Mainland China: a systematic review and meta-analysis

Introduction Acne, a very common skin disease, can result in psychological distress and sustain impairment in quality of life. Data on the prevalence of acne and the differences in gender, region and age are limited. The aim of this review is to estimate the prevalence of acne in Mainland China comprehensively and to quantify its association with gender, region and age. Methods We searched electronic databases with predetermined search terms to identify relevant studies published between 1 January 1996 and 30 September 2016. We pointed out repeated results using Note Express software and evaluated the studies for inclusion. Two independent reviewers extracted the data, followed with statistical analyses using Comprehensive Meta-Analysis software version 2.0. A random effects model was adopted to calculate the overall pooled prevalence and to merge categories, including gender (males and females), region (Northern China and Southern China) and age (primary and secondary students: 7-17 years old; undergraduates: 18-23 years old; overall: no limits of age) for subgroup analyses. Logistic meta-regression analysis was used to clarify the associations between acne and the predictors age, gender and region using OR and their associated 95% CI. Results 25 relevant studies were included in this meta-analysis. The overall pooled prevalence rates of acne were 39.2% (95% CI 0.310 to 0.479). The prevalence rates in different age groups were 10.2% overall (95% CI 0.059 to 0.171), 50.2% for primary and secondary students (95% CI 0.451 to 0.554), and 44.5% for undergraduates (95% CI 0.358 to 0.534); by gender, the prevalence rates were 35.7% for females (95% CI 0.275 to 0.448) and 39.7% for males (95% CI 0.317 to 0.482); and by region, the prevalence rates were 34.2% for Northern China (95% CI 0.242 to 0.458) and 46.3% for Southern China (95% CI 0.374 to 0.555). The associations between acne and the predictors age, gender and region were statistically significant. Conclusions In Mainland China, primary and secondary students exhibited higher prevalence rates than undergraduate students; males had higher prevalence rates of acne than females; and the prevalence rates of acne in Southern China was higher than Northern China.