To examine whether the degree of stress associated with adverse physical side effects correlates with overall quality of life (QOL) and compliance rates. To determine if instruments used to assess QOL can detect differences between treatments that have no known central nervous system effects.
Patients and Methods
This randomized, double-blind, parallel group study evaluated 180 to 480 mg of controlled onset, extended release (COER)-verapamil (n = 259) or 30 to 120 mg/d of nifedipine gastrointestinal therapeutic system (GITS) (n = 269) in men and women between 21 and 80 years of age with stages 1 to 3 hypertension. A battery of questions evaluating psychological well-being and a physical symptom distress index was administered after a 4-week placebo washout (baseline) and after 10 weeks of treatment or at dropout.
Both treatments effectively lowered blood pressure, and there were no significant between-group differences in psychosocial QOL. A difference in the level of physical symptom distress was detected between treatments (P = .002; multivariate analysis of variance), with 7 significant univariate treatment effects, all favoring COER-verapamil, being noted—pedal edema, polyuria, rapid heart beat or palpitations, hives, muscle cramps, abdominal cramps, and headaches. Constipation-related distress increased significantly (P = .001) but to a similar extent with both treatments. The difference in symptom distress tended to predict compliance as there were more withdrawals in the nifedipine GITS group (n = 85) vs COER-verapamil group (n = 64) (P = .08).
Patient-assessed physical symptom distress is a sensitive, simple technique to evaluate the effect of antihypertensive medications on QOL and tolerability, as shown by its ability to detect the improvement associated with COER-verapamil. Depending on the agents involved, the Physical Symptom Distress Index may more closely predict dropout rates than the traditional psychosocial instruments, as suggested by the lower dropout rate in the COER-verapamil group. Thus, in studying treatment effects on QOL, both the distress of physical symptoms and the impact of psychosocial factors should be evaluated.