Effects of Polypharmacy on Adverse Drug Reactions among Geriatric outpatients at a Tertiary Care Hospital in Karachi, A prospective cohort study
The overall aims of the study are to estimate the ADRs due to poly-pharmacy among the geriatric cohort attending outpatient clinics at a tertiary care center and to determine the strength of association of ADRs due to poly-pharmacy in the mentioned population.
METHODS:
A hospital based prospective cohort study was conducted at ambulatory care clinics of Aga Khan University between January to December 2012. One thousand geriatrics patients (age > 65 years) visiting clinics were identified. They were divided on the basis of exposure (poly pharmacy vs. no poly pharmacy). We followed them from the time of their enrollment (day zero) to once weekly till six weeks. Incidence was calculated and Cox proportional hazard model estimate was used.
RESULTS:
The occurrence of poly pharmacy was 68%. The incidence of ADRs with poly pharmacy was 10.5%. Majority (30%) patients cannot read or write. Use of herbal medicine was reported by 3.2% and homeopathic by 3%. Our Cox adjusted model shows that poly pharmacy was 2.3 times more associated with ADRs, con-current homeopathic use was 7.4 times and those who cannot read and write was 1.5 times more associated with ADRs.
CONCLUSIONS:
The incidence of ADRs due to poly pharmacy is alarmingly high. The factors associated with ADRs are modifiable. Policies need be design to strengthen the prescription pattern.