Risks and benefits of antihypertensive medications in older adults--reply

Association between gaps in antihypertensive medication adherence and injurious falls in older community-dwelling adults: a prospective cohort study

OBJECTIVE

Growing evidence suggests that older adults are at an increased risk of injurious falls when initiating antihypertensive medication, while the evidence regarding long-term use of antihypertensive medication and the risk of falling is mixed. However, long-term users who stop and start these medications may have a similar risk of falling to initial users of antihypertensive medication. Our aim was to evaluate the association between gaps in antihypertensive medication adherence and injurious falls in older (≥65 years) community-dwelling, long-term (≥≥1 year) antihypertensive users.

DESIGN

Prospective cohort study.

SETTING

Irish Community Pharmacy.

PARTICIPANTS

Consecutive participants presenting a prescription for antihypertensive medication to 106 community pharmacies nationwide, community-dwelling, ≥65 years, with no evidence of cognitive impairment, taking antihypertensive medication for ≥1 year (n=938).

MEASURES

Gaps in antihypertensive medication adherence were evaluated from linked dispensing records as the number of 5-day gaps between sequential supplies over the 12-month period prior to baseline. Injurious falls during follow-up were recorded via questionnaire during structured telephone interviews at 12 months.

RESULTS

At 12 months, 8.1% (n=76) of participants reported an injurious fall requiring medical attention. The mean number of 5-day gaps in medication refill behaviour was 1.47 (SD 1.58). In adjusted, modified Poisson models, 5-day medication refill gaps at baseline were associated with a higher risk of an injurious fall during follow-up (aRR 1.18, 95% CI 1.02 to 1.37, p=0.024).

CONCLUSION

Each 5-day gap in antihypertensive refill adherence increased the risk of self-reported injurious falls by 18%. Gaps in antihypertensive adherence may be a marker for increased risk of injurious falls. It is unknown whether adherence-interventions will reduce subsequent risk. This finding is hypothesis generating and should be replicated in similar populations.

A Tale of 3 Trials: ACCORD, SPRINT, and SPS3. What Happened?

Within the last several years, the National Institutes of Health has supported three randomized clinical trials to determine whether lower than usually recommended goals for treatment of hypertension would have greater benefit for prevention of cardiovascular disease and stroke. These were the ACCCORD, SPRINT, and Secondary Prevention of Small Subcortical Strokes (SPS3) Trials. Together they enrolled 17,114 participants. Results for all three have been reported. The trials differ from each other in their inclusion criteria, target blood pressures for the lower goal (intensive treatment), but are similar in many respects. The results with regard to their primary outcome were different: not significant for ACCORD and SPS3, but definitely significant for SPRINT. Subgroup analysis revealed differences and similarities. When viewed together and with recent large observational studies, they support a conclusion that a systolic pressure in the range of 125-135 mm Hg range is likely to be optimal on treatment for most hypertensive patients.

Functional Status and Antihypertensive Therapy in Older Adults: A New Perspective on Old Data

BACKGROUND

Functional status may be useful for identifying older adults who benefit from lower blood pressure. We examined whether functional status modifies the effect of antihypertensive treatment among older adults.

METHODS

Post hoc analyses of the Systolic Hypertension in the Elderly Program (SHEP), a randomized trial of antihypertensive therapy vs. placebo (1985-1991) in 4,736 adults aged 60 years or older with isolated systolic hypertension. Outcomes were all-cause death, cardiovascular (CV) death, myocardial infarction (MI), stroke, falls, and symptoms of hypotension. The effect modifier of interest was functional status, assessed by self-reported physical ability limitation (PAL).

RESULTS

Among persons with no PAL, those receiving treatment had a lower rate of death, CV death, and MI compared with placebo (4.0, 2.9, and 4.2 per 1,000 person-years lower, respectively). In contrast, among persons with a PAL, those receiving treatment had a higher rate of death, CV death, and MI compared with placebo (8.6, 5.3, and 2.7 per 1,000 person-years higher, respectively). These patterns persisted in Cox models, although interaction terms did not reach statistical significance. Treatment remained protective for stroke regardless of functional status. The rate of falls associated with treatment differed by functional status; incidence-rate ratio = 0.81, 95% confidence interval (CI) = (0.66, 0.99), and 1.32, 95% CI = (0.87, 2.00) in participants without and with a PAL, respectively, in models adjusted for demographics and baseline blood pressure (P-value for interaction, 0.04).

CONCLUSIONS

Functional status may modify the effect of antihypertensive treatment on MI, mortality, and falls, but not stroke, in older adults. Functional status should be examined in other trial settings.