Factors associated with high medication regimen complexity in primary care older adults in Brazil

Complex medication regimens are common among older adults and contribute to the occurrence of undesirable health outcomes. This study aims to investigate the factors associated with high medication regimen complexity in older people.

A cross-sectional study was conducted with older adults selected from two primary healthcare units. Medication regimen complexity was measured using the Brazilian version of the Medication Regimen Complexity Index. The Pearson's Chi square test was used to analyse the individual association of each independent variable with high medication regimen complexity. The backward stepwise method was used to obtain the final multivariate logistic regression model.

We included 227 older adults with a median age of 70 years who were mostly females (70.9%). The median total Medication Regimen Complexity Index was 20.8 for high complexity and 10.5 for patients that were not using high complexity regimens. The Medication Regimen Complexity Index section with higher median scores in both groups was dosing frequency, followed by additional instructions. High complexity was associated with diabetes (OR 5.42; p = 0.00 2.69-10.93) and asthma/Chronic Obstructive Pulmonary Disease (OR 2.96(1.22-7.18); p = 0.02).

Older people in primary care with diabetes and respiratory disease were most likely to have complex medication regimens. Dosing frequency and additional instructions were medication regime complexity index components that most contributed to the high complexity in medication regime of older adults.