title: Correction of sampling bias in a cross-sectional study of post-surgical complications.
abstract: Cross-sectional designs are often used to monitor the proportion of infections and other post-surgical complications acquired in hospitals. However, conventional methods for estimating incidence proportions when applied to cross-sectional data may provide estimators that are highly biased, as cross-sectional designs tend to include a high proportion of patients with prolonged hospitalization. One common solution is to use sampling weights in the analysis, which adjust for the sampling bias inherent in a cross-sectional design. The current paper describes in detail a method to build weights for a national survey of post-surgical complications conducted in Israel. We use the weights to estimate the probability of surgical site infections following colon resection, and validate the results of the weighted analysis by comparing them with those obtained from a parallel study with a historically prospective design.
authors.affiliation: Department of Health Services Research, Ministry of Health, 29 Rivka Street, 91010 Jerusalem, Israel. rfluss@gmail.com
authors.forename: Ronen
authors.initials: R
authors.lastname: Fluss
authors.forename: Micha
authors.initials: M
authors.lastname: Mandel
authors.forename: Laurence S
authors.initials: LS
authors.lastname: Freedman
authors.forename: Inbal Salz
authors.initials: IS
authors.lastname: Weiss
authors.forename: Anat Ekka
authors.initials: AE
authors.lastname: Zohar
authors.forename: Ziona
authors.initials: Z
authors.lastname: Haklai
authors.forename: Ethel-Sherry
authors.initials: ES
authors.lastname: Gordon
authors.forename: Elisheva
authors.initials: E
authors.lastname: Simchen
mesh_terms: D000465:Algorithms; D015982:Bias; D056808:Biostatistics; D003106:Colon / Q000601:surgery; D003430:Cross-Sectional Studies / Q000706:statistics & numerical data; D003625:Data Collection; D006801:Humans; D007557:Israel / Q000453:epidemiology; D015233:Models, Statistical; D016017:Odds Ratio; D011183:Postoperative Complications / Q000453:epidemiology*; D015995:Prevalence; D012307:Risk Factors; D013530:Surgical Wound Infection / Q000453:epidemiology