Table 2

Methodological quality of the studies reporting the prevalence of acne in Mainland China

Name	Sampling scheme	Population characteristics	Prevalence definition	Diagnostic criteria	Response rate %	Score
Zhang Feng²⁷	Random stratified sample	Adequate	Clear	Clear	95	4
Liu Lijuan³⁵	Random stratified sample	Adequate	Clear	Clear	N/A	3
Liu Qing³⁶	Cluster sampling	Adequate	Clear	Clear	48.5	3
Li Shengjie³⁴	Random stratified sample	Adequate	Clear	Clear	100	4
Zhang Zhiyong⁴⁰	Cluster sampling	Adequate	Clear	Clear	97.75	4
Cai Luanduan²⁵	Random stratified sample	Adequate	Clear	Clear	98.05	4
Zhang Jian²⁰	Random stratified sample	Adequate	Clear	Clear	N/A	3
Wang Renli⁴¹	Random stratified sample	Adequate	Clear	Clear	N/A	3
Pei Guangde³⁷	Random stratified sample	Adequate	Clear	Clear	53.4	3
Chen Ying²¹	Random stratified sample	Adequate	Clear	Clear	90.8	4
Zhang Hong³⁹	Cross-sectional	Adequate	Clear	Clear	N/A	3
Deng Bin³¹	Random stratified sample	Adequate	Clear	Clear	N/A	3
Cui Jianping³⁰	Random stratified sample	Adequate	Clear	Clear	98.1	4
Li Min²²	Random stratified sample	Adequate	Clear	Clear	N/A	3
Feng Jieying²⁴	Random stratified sample	aAequate	Clear	Clear	98.24	4
Gao Aili³²	Cross-sectional	Adequate	Clear	Clear	96.2	4
Wu Tieqiang²⁶	Cross-sectional	Adequate	Clear	Clear	98.84	4
Sun Zhenxiu²³	Random stratified sample	Adequate	Clear	Clear	N/A	3
Liu Zhaorui²⁸	Random stratified sample	Adequate	Clear	Clear	N/A	3
Zhang Aihua³⁸	Random stratified sample	Adequate	Clear	Clear	N/A	3
Fu Rui²⁹	Cross-sectional	Adequate	Clear	Clear	99.06	4
Li Bing³³	Random stratified sample	Adequate	Clear	Clear	95.2	4
Shen Yiwei ¹⁰	Community-based study	Adequate	Clear	Clear	86.84	4
Law MP¹¹	Cross-sectional	Adequate	No	Clear	99.3	4
Wu TQ¹²	Cross-sectional	Adequate	Clear	Clear	98.8	4

N/A, not available.