“…Several studies reported stratified results by dosage, 5,7,28,29,39 concomitant medication use or polypharmacy, 7,40,44,87,106 duration, 32,96 comorbidity, 36,38,40,44 race 34 and nursing home residence. 26 For other studies, analyses were adjusted by age, 20,22,30,52,71,91,121 sex, 20,22,30,52,71,74,84,121 race, 22,121 dose, 52,71 nursing home residence, 22 concomitant medication or polypharmacy, 22,52,71 comorbidity, 121 with some studies conducting adjusted analyses but not reporting the independent association of these covariates. 23,27,31,90,119,120 Length of follow up ranged from one month 55,93,109,…”