Figure 3. Propensity score matching diagnostics in the ADNI and MemClin datasets. (A) Patient counts after matching are shown as a function of their individual propensity score and overlayed with density plots, stratified by level of cognitive impairment. (B) Mean distance followed by single-covariate balance by group calculated before (Unadjusted) and after (Adjusted) matching. ADNI matched: n CI= 392, n NCI = 392. MemClin matched: n CI = 143, n NCI = 143. ADNI, Alzheimer’s Disease Neuroimaging Initiative; MemClin, Memory Clinic Project; CI, cognitive impairment; NCI, no cognitive impairment.