Adding a New Medication Versus Maximizing Dose to Intensify Hypertension Treatment in Older Adults : A Retrospective Observational Study

Abstract

Background: There are 2 approaches to intensifying antihypertensive treatment when target blood pressure is not reached, adding a new medication and maximizing dose. Which strategy is better is unknown.

Objective: To assess the frequency of intensification by adding a new medication versus maximizing dose, as well as the association of each method with intensification sustainability and follow-up systolic blood pressure (SBP).

Design: Large-scale, population-based, retrospective cohort study. Observational data were used to emulate a target trial with 2 groups, new medication and maximizing dose, who underwent intensification of their drug regimen.

Setting: Veterans Health Administration (2011 to 2013).

Patients: Veterans aged 65 years or older with hypertension, an SBP of 130 mm Hg or higher, and at least 1 antihypertensive medication at less than the maximum dose.

Measurements: The following 2 intensification approaches were emulated: adding a new medication, defined as a total dose increase with new medication, and maximizing dose, defined as a total dose increase without new medication. Inverse probability weighting was used to assess the observational effectiveness of the intensification approach on sustainability of intensified treatment and follow-up SBP at 3 and 12 months.

Results: Among 178 562 patients, 45 575 (25.5%) had intensification by adding a new medication and 132 987 (74.5%) by maximizing dose. Compared with maximizing dose, adding a new medication was associated with less intensification sustainability (average treatment effect, -15.2% [95% CI, -15.7% to -14.6%] at 3 months and -15.1% [CI, -15.6% to -14.5%] at 12 months) but a slightly larger reduction in mean SBP (-0.8 mm Hg [CI, -1.2 to -0.4 mm Hg] at 3 months and -1.1 mm Hg [CI, -1.6 to -0.6 mm Hg] at 12 months).

Limitation: Observational data; largely male population.

Conclusion: Adding a new antihypertensive medication was less frequent and was associated with less intensification sustainability but slightly larger reductions in SBP. Trials would provide the most definitive support for our findings.

Primary funding source: National Institute on Aging and Veterans Health Administration.

Figure 1.. Study design.

Figure caption: This figure illustrates the analytic approach that we applied to observational healthcare data to emulate a trial as if patients were assigned to one of two different intensification approaches. Eligible patients (≥65 years old, established VA primary care, already on ≥1 antihypertensive medication not at full dose) were assigned at T₀ to either adding a new medication or maximizing dose. The figure demonstrates how we developed treatment, survival and censoring weights for the two different outcomes (intensification sustainability and follow-up SBP). Abbreviations: M, month; SBP, systolic blood pressure; PS, propensity score; SBP, systolic blood pressure; T, time. ¹ Treatment weights calculation: PS with new medication as outcome. Independent variables: age, baseline comorbidities (see Supplemental Table 1), baseline medication count, baseline medication classes (yes/no for each class), geriatric care, hypertension-treating specialty care, baseline SBP, facility, community-based outpatient clinic, VA medical center, facility complexity level, proportion of geriatric care in the facility, and proportion of specialty care in the facility. ² Survival weights calculation: PS with survival at +3M or +12M as outcome; same independent variables as for treatment weights calculation. ³ Censoring weights calculation: PS with composite outcome of survival and at least one SBP measurement at +3M or +12M; same independent variables as for treatment weights calculation.

Figure 2.

Change in systolic blood pressure between baseline and follow-up according to intensification approach and baseline systolic blood pressure.