Study on comparison of combination treatment in hypertension

Hi Seng: The study diagnostics suggest that the propensity score
adjustment strategy did not achieve adequate balance in many covariates.
This can happen for several different reasons, including: 1) the size of
one or both of the cohorts was small, so that the propensity score model
did not have sufficient data to fit a good predictive model. 2) the two
cohorts were very different and there are one or more highly predictive
covariates that could discriminate the group (of which, some may be
covariates that should be excluded from model fitting, 3) the adjustment
strategy (matching/stratification) did not create well-balanced strata,
Given what you have shared here, I suspect it might be either #1 or #2
(not likely #3 since you are doing 1-1 matching).