Thesis (H.P.H.)--Chulalongkorn University, 2013

The aims of study are to know the prevalence of, and to describe factors associated with prescribing PIM at a district hospital in the south of Thailand. In this cross-sectional study, the elderly patients were a ≥ 65-year outpatient and had at least 1 prescribed medication from the hospital. Overall patients were 430 with 2,128 prescriptions. 2012 Beers criteria were applied to detect PIM. Prevalence of PIM was calculated by their total prescriptions. Prescription, patient, and prescriber characteristics associated with PIM were analyzed by logistic regression. Results showed that 28% of total prescriptions had at least 1 PIM. There was the more likelihood of PIM prescription at outpatient department increased significantly when that prescription comprised of more than 5 medications (p<0.001). The positive association between age of participant and the presence of PIM prescription was observed (OR=1.018, p= 0.040, CI=1.001-1.035). Interestingly, the elderly outpatients who had more frequent outpatient visits had less PIM prescription as compared to reference group, who had 1-3 visits. (4-6 vs. ≥7: OR = 0.581 [95%CI=0.408-0.828], p=0.003 vs. OR=0.704 [95%CI=0.526-0.943], p=0.019) No statistically significant association between the presence of PIM and patient's gender, number of diagnoses, Types of health insurance schemes, hospitalizations, prescriber's gender, ages, types of prescriber and length of prescriber's years work was observed.