השוואת שיטות

	סדרת מקרים מותאמת סיכון	התאמת ציון נטייה
תחום	אפידמיולוגיה	סטטיסטיקה למחקר
משפחה	Process / pipeline	Process / pipeline
שנת המקור	1990s–2000s	1983
הוגה השיטה	Copeland, Jones & Walters (POSSUM score, 1991); broader risk-adjustment methodology developed across surgical and critical care audit literature	Paul Rosenbaum and Donald Rubin
סוג	Observational study design with statistical risk correction	Method
מקור מכונן	Copeland, G. P., Jones, D., & Walters, M. (1991). POSSUM: a scoring system for surgical audit. British Journal of Surgery, 78(3), 355–360.	Rosenbaum, P. R., & Rubin, D. B. (1983). The central role of the propensity score in observational studies for causal effects. Biometrika, 70(1), 41–55.
כינויים	risk-stratified case series, adjusted case series, risk-corrected case series	PSM, propensity score weighting, covariate balance
קשורות	5	3
תקציר	A risk-adjusted case series is an observational study design that reports outcomes for a consecutive or defined group of patients undergoing the same procedure or sharing a condition, while statistically correcting for differences in patient-level baseline risk. Rather than presenting raw complication or mortality rates, it compares observed outcomes against expected rates derived from a validated scoring model (e.g., POSSUM, APACHE, ASA grade), enabling fairer evaluation of clinical performance across institutions or over time.	Propensity score matching (PSM) is a method for reducing confounding bias in observational studies by balancing baseline characteristics between treatment groups, simulating randomization. Developed by Rosenbaum and Rubin (1983), it estimates the probability of receiving treatment given observed covariates, then matches or weights treated and control individuals with similar treatment probabilities. Widely used in medicine, epidemiology, and policy evaluation when randomized trials are infeasible or unethical, enabling estimation of treatment effects while controlling for selection bias.