Is adherence to drug treatment correlated with health-related quality of life?
BACKGROUND
Adherence to drug treatment and health-related quality of life (HRQL) are two distinct concepts. Generally one would expect a positive relationship between the two.


OBJECTIVE
The purpose of this study was to assess the relationship between adherence and HRQL.


METHODS
HRQL was measured using the physical and mental summary measures of the RAND-12 (PHC-12, MHC-12), the SF-12 (PCS-12, MCS-12), HUI-2 and HUI-3. Adherence was assessed using Morisky's instrument. Three longitudinal datasets were used. One dataset included 100 hypertensive patients. Another dataset covered 199 high risk community-dwelling individuals. The third dataset consisted of 365 elderly patients. Spearman's correlation coefficients were used to assess association. Subgroup analyses by type of medication and inter-temporal analyses were also performed.


RESULTS
Correlation between adherence and PHC-12 ranged from 0.08 (p = 0.26) to 0.22 (p < 0.01). Correlations between adherence and MHC-12 ranged from 0.11 (p = 0.11) to 0.15 (p < 0.01). Similar results were observed using HUI-2, HUI-3, and SF-12 as well as by type of medication and in the lagged analyses.


CONCLUSIONS
Correlations between HRQL and adherence were positive but typically weak or negligible in magnitude.
D000368:Aged; D002170:Canada; D004358:Drug Therapy; D005260:Female; D006302:Health Services Research; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D011788:Quality of Life; D012646:Self Administration