The Effects of Mandatory Prescribing of Thiazides for Newly Treated, Uncomplicated Hypertension: Interrupted Time-Series Analysis

Abstract

BackgroundThe purpose of our study was to evaluate the effects of a new reimbursement rule for antihypertensive medication that made thiazides mandatory first-line drugs for newly treated, uncomplicated hypertension. The objective of the new regulation was to reduce drug expenditures.Methods and FindingsWe conducted an interrupted time-series analysis on prescribing data before and after the new reimbursement rule for antihypertensive medication was put into effect. All patients started on antihypertensive medication in 61 general practices in Norway were included in the analysis. The new rule was put forward by the Ministry of Health and was approved by parliament. Adherence to the rule was monitored only minimally, and there were no penalties for non-adherence. Our primary outcome was the proportion of thiazide prescriptions among all prescriptions made for persons started on antihypertensive medication. Secondary outcomes included the proportion of patients who, within 4 mo, reached recommended blood-pressure goals and the proportion of patients who, within 4 mo, were not started on a second antihypertensive drug. We also compared drug costs before and after the intervention. During the baseline period, 10% of patients started on antihypertensive medication were given a thiazide prescription. This proportion rose steadily during the transition period, after which it remained stable at 25%. For other outcomes, no statistically significant differences were demonstrated. Achievement of treatment goals was slightly higher (56.6% versus 58.4%) after the new rule was introduced, and the prescribing of a second drug was slightly lower (24.0% versus 21.8%). Drug costs were reduced by an estimated Norwegian kroner 4.8 million (€0.58 million, US$0.72 million) in the first year, which is equivalent to Norwegian kroner 1.06 per inhabitant (€0.13, US$0.16).ConclusionsPrescribing of thiazides in Norway for uncomplicated hypertension more than doubled after a reimbursement rule requiring the use of thiazides as the first-choice therapy was put into effect. However, the resulting savings on drug expenditures were modest. There were no significant changes in the achievement of treatment goals or in the prescribing of a second antihypertensive drug.

Combination of prescribing restrictions and policies to engineer low prices to reduce reimbursement costs

“…This resulted in the instigation of 'preferred drug(s)' among specific classes, mirroring the situation in other European countries [3,16,18,20,26]. In March 2004, prescribing restrictions were successfully introduced for certain drug classes to treat essential hypertension with thiazides instigated as first-line treatment [27]. In June 2005, prescribing restrictions were introduced for certain statins following the availability of generic simvastatin [17,101].…”

National Utilization of Antihypertensive Medications From 2000 to 2006 in the Veterans Health Administration: Focus on Thiazide Diuretics

“…Performance measures may prompt clinicians to improve thiazide use in patients with complicated hypertension (ie, those with compelling indications) who are already receiving appropriate medication for the specific comorbidity but who might benefit from the addition of a thiazide diuretic. We note that in Norway, implementation of a mandatory prescribing rule whereby a thiazide diuretic was the only drug class that would be reimbursed as initial therapy for uncomplicated hypertension increased thiazide diuretic use from approximately 10% to nearly 25% after the health care policy intervention 31 …”

“…Clinical trial evidence and clinical practice guideline recommendations impact prescribing practices, although the effect may be less than desired for a variety of reasons including differing recommendations from guidelines published outside the United States. In addition, evaluation of risk vs benefit to the patient based on potential adverse events or contraindications, provider or patient resistance to change, and the influence of marketing 19,30 may have an impact and require specific interventions to change prescribing practices 24,31–33 . There can also be a lag time in the development and approval of the VHA/DoD clinical practice guideline recommendations.…”

A cluster randomized trial to measure the impact on nonsteroidal anti-inflammatory drug and proton pump inhibitor prescribing in Italy of distributing cost-free paracetamol to osteoarthritic patients

“…Many studies have showed the effect of reimbursement policies on drug prescriptions and consumptions [11, 12]; most of the studies included in two recent systematic reviews looked at the effect of restrictions on reimbursement, [12] cap payment, or co-payment strategies [11]. Only a few studies have observed the effect of relaxation or exemption from restriction strategies to induce the use of appropriate and effective drugs that may be underprescribed or under-used [13–17].…”