What question did this study set out to answer?

To compare patient adherence and persistence between hydrochlorothiazide (HCTZ) monotherapy and fixed-dose combination therapies containing HCTZ in patients initiating antihypertensive treatment.

November 6, 2008BMC Family PracticeOpen Access

Improved persistence and adherence to diuretic fixed-dose combination therapy compared to diuretic monotherapy

Q: What is the clinical evidence from this study?

Study design: Cohort. Population: Hypertension (n=48212). Intervention: Fixed-dose combinations containing HCTZ (ARB/HCTZ, ACEI/HCTZ, BB/HCTZ) vs. HCTZ monotherapy. Primary outcome: Persistence at 12 months (OR 0.37, 95% CI 0.36-0.38, p=<0.01).

View Full Paper

Ask AI

Bookmark

Key result

Initiating antihypertensive therapy with a fixed-dose combination of HCTZ and an ARB, ACEI, or BB was associated with significantly greater persistence at 12 months compared to HCTZ monotherapy (e.g., 52.6% vs 29.9% for ARB/HCTZ vs HCTZ).

Why the study?

Does fixed-dose combination therapy with HCTZ improve persistence and adherence compared to HCTZ monotherapy in patients initiating antihypertensive therapy?

Population

48,212 patients initiating antihypertensive therapy with no prescription claims for any antihypertensive…

Comparison

Fixed-dose combination therapy containing… vs Hydrochlorothiazide (HCTZ) monotherapy

Design

Cohort

Follow-up

1 year

Authors

BPBimal V. PatelTandem Diabetes Care (United States)RRRosemay A. Remigio‐BakerGovernment of Russia PTPatrick ThiebaudPfizer (United States)

Discussion

Member takes

Implication

Fixed-dose HCTZ combinations were associated with greater persistence than monotherapy; leaves open whether this improves clinical outcomes.

Key Points

To compare patient adherence and persistence between hydrochlorothiazide (HCTZ) monotherapy and fixed-dose combination therapies containing HCTZ in patients initiating antihypertensive treatment.
Retrospective cohort analysis of 48,212 patients (mean age 53.7 years; 66.5% female) initiating HCTZ monotherapy or fixed-dose combinations (ARB/HCTZ, ACEI/HCTZ, or BB/HCTZ) between 2001 and 2003.
Required six months of pre-index eligibility without antihypertensive therapy and continuous enrollment for one year of follow-up.
Evaluated 12-month persistence, medication possession ratio (MPR), and proportion of days covered (PDC) using multivariable logistic regression adjusted for demographics, comorbidities, copay, and cardiovascular medications.
Twelve-month persistence was significantly lower with HCTZ monotherapy (29.9%) compared to ARB/HCTZ (52.6%; OR = 0.37, 95% CI 0.36–0.38), ACEI/HCTZ (51.4%; OR = 0.38, 95% CI 0.37–0.39), and BB/HCTZ (51.9%; OR = 0.38, 95% CI 0.37–0.40).
Proportion of days covered was significantly lower for HCTZ monotherapy (32.5%) compared to ARB/HCTZ (53.7%; OR = 0.39, 95% CI 0.37–0.40), ACEI/HCTZ (50.9%; OR = 0.42, 95% CI 0.40–0.43), and BB/HCTZ (51.3%; OR = 0.44, 95% CI 0.42–0.45).
Medication possession ratio (MPR) and adherence defined as MPR >80% were also significantly lower in patients receiving HCTZ monotherapy relative to all fixed-dose combination regimens.

Study Design

Type

Cohort (n=48,212)

Structured PICO

Does fixed-dose combination therapy with HCTZ improve persistence and adherence compared to HCTZ monotherapy in patients initiating antihypertensive therapy?

Population

48,212 adult patients newly initiated on antihypertensive therapy, followed for 1 year to assess medication persistence and adherence.

Exposure

Fixed-dose combination therapy containing hydrochlorothiazide (HCTZ) with an angiotensin-receptor blocker (ARB/HCTZ), angiotensin-converting enzyme inhibitor (ACEI/HCTZ), or beta blocker (BB/HCTZ)

Comparator

Hydrochlorothiazide (HCTZ) monotherapy

Outcome

Persistence, medication possession ratio (MPR), adherence (MPR >80%), and proportion of days covered (PDC) with initial antihypertensive therapy at 1 year

Main Result

Odds Ratio: 0.37 (95% CI 0.36–0.38)

Absolute Event Rate: 52.6% vs 29.9%

p-value: p=<0.01

Initiating antihypertensive treatment with a fixed-dose combination containing HCTZ is associated with significantly greater 1-year persistence and adherence compared to HCTZ monotherapy.

Limitations

Medical claims were unavailable to confirm hypertension diagnosis.
Drug utilization metrics were measured by prescription refill patterns and not actual drug taken.
Unmeasured confounding factors may have played a role in physician treatment selection.
Patient blood pressure was not available for analysis.
Included only fixed-dose combinations with HCTZ and excluded free combination regimens.

Cite This Study

Patel et al. (2008) conducted a cohort in Hypertension (n=48,212). Fixed-dose combinations containing HCTZ (ARB/HCTZ, ACEI/HCTZ, BB/HCTZ) vs. HCTZ monotherapy was evaluated on Persistence at 12 months (OR 0.37, 95% CI 0.36-0.38, p=<0.01). Initiating antihypertensive therapy with a fixed-dose combination of HCTZ and an ARB, ACEI, or BB was associated with significantly greater persistence at 12 months compared to HCTZ monotherapy (e.g., 52.6% vs 29.9% for ARB/HCTZ vs HCTZ).

synapsesocial.com/papers/6a6f1b50439bab0cabc2af3b https://doi.org/10.1186/1471-2296-9-61

View Full Paper

Ask AI

Bookmark

Implication

Fixed-dose HCTZ combinations were associated with greater persistence than monotherapy; leaves open whether this improves clinical outcomes.