[Quality analysis of observational studies on pelvic organ prolapse in China]

Objective: To evaluate the quality of observational studies on pelvic organ prolapse in China. Methods: The checklist of strengthening the reporting of observational studies in epidemiology (STROBE) statement was applied to evaluate the observational studies. The articles were searched in the SinoMed database using the terms: prolapse, uterine prolapse, cystocele, rectal prolapse and pelvic floor; limited to Chinese core journals in obstetrics and gynecology from January 1996 to December 2015. With two 10-year groups (1996-2005 and 2006-2015), the χ(2) test was used to evaluate inter-group differences. Results: (1) A total of 386 observational studies were selected, including 15.5%(60/386) of case-control studies, 80.6%(311/386) of cohort studies and 3.9% (15/386) of cross-sectional studies. (2) There were totally 22 items including 34 sub-items in the checklist. There were 17 sub-items (50.0%, 17/34) had a reporting ratio less than 50% in all of aticles, including: 1a (study's design) 3.9% (15/386), 6a (participants) 24.6% (95/386), 6b (matched studies) 0 (0/386), 9 (bias) 8.3% (32/386), 10 (study size) 3.9%, 11 (quantitative variables) 41.2% (159/386), 12b-12e (statistical methods in detail) 0-2.6% (10/386), 13a (numbers of individuals at each stage of study) 18.9% (73/386), 13b (reasons for non-participation at each stage) 18.9%, 13c (flow diagram) 0, 16b and 16c (results of category boundaries and relative risk) 9.6% (37/386) and 0, 19 (limitations) 31.6% (122/386), 22 (funding) 20.5% (79/386). (3) The quality of articles published in the two decades (1996-2005 and 2006-2015) were compared, and 38.2%(13/34) of sub-items had been significantly improved in the second 10-year (all P<0.05). The improved items were as follows: 1b (integrity of abstract), 2 (background/rationale), 6a (participants), 7 (variables), 8 (data sources/measurement), 9 (bias), 11 (quantitative variables), 12a (statistical methods), 17 (other analyses), 18 (key results), 19 (limitations), 21 (generalisability), 22 (funding). Conclusions: The quality of observational studies on POP in China is suboptimal in half of evaluation items. However, the quality of articles published in the second 10-year have significantly improved.