Thiazide Prescribing Research Articles

Risk of falls associated with antihypertensive medication: population-based case-control study

antihypertensive medications have long been implicated as a potential cause of falls in older people but, despite their widespread prescribing, the size of class-specific adverse effects remains unclear. to determine the role of antihypertensive medications in older people with a recorded fall in primary care. case-control study. UK general practices contributing data to The Health Improvement Network primary care database. patients over 60 years of age with a first fall recorded between 2003 and 2006 were selected, and up to six controls per case matched by age, gender and general practice. We used conditional logistic regression to estimate odds ratios for ever exposure, and current/previous exposure to the main classes of antihypertensives, adjusting for co-morbidity. We also examined the effect of the time interval from first prescription to first fall. amongst our 9,682 cases, we found an increased risk of current prescribing of thiazides (odds ratio (OR) 1.25; 95% confidence interval 1.15-1.36). At 3 weeks after first prescribing the risk remained 4.28 (1.19-15.42). We found a reduced risk for current prescribing of beta blockers (OR 0.90; 0.85-0.96). There was no significant association with current prescribing of any other class of antihypertensive. the study provides evidence that current prescribing of thiazides is associated with an increased risk of falling and that this is strongest in the 3 weeks following the first prescription.

Part I, patient perspective: activating patients to engage their providers in the use of evidence-based medicine: a qualitative evaluation of the VA Project to Implement Diuretics (VAPID).

BackgroundThis qualitative evaluation follows a randomized-control trial of a patient activation intervention in which hypertensive patients received a letter in the mail asking them to discuss thiazide diuretics with their provider. Results of the parent study indicated that the intervention was effective at facilitating discussions between patients and providers and enhancing thiazide prescribing rates. In the research presented here, our objective was to interview patients to determine their receptivity to patient activation, a potential leverage point for implementing interventions.MethodsSemi-structured phone interviews were conducted with 54 patients, purposefully sampled from a randomized controlled trial of a patient activation intervention. All subjects had a history of hypertension and received primary care from one of twelve Veterans Affairs primary care clinics. All interviews were transcribed verbatim and reviewed by the interviewer. Interviews were independently coded by three qualitative researchers until consensus was attained, and relevant themes and responses were identified, grouped, and compared. NVivo 8.0 was used for data management and analysis.ResultsData from this qualitative study revealed that most participants held favorable opinions toward the patient activation intervention used in the clinical trial. Most (82%) stated they had a positive reaction. Patients emphasized they liked the intervention because it was straightforward and encouraged them to initiate discussions with their provider. Also, by being active participants in their healthcare, patients felt more invested. Of the few patients offering negative feedback (11%), their main concern was discomfort with possibly challenging their providers' healthcare practices. Another outcome of interest was the patients' perceptions of why they were or were not prescribed a thiazide diuretic, for which several clinically relevant reasons were provided.ConclusionPatients' perceptions of the intervention indicated it was effective via the encouragement of dialogue between themselves and their provider regarding evidence-based treatment options for hypertension. Additionally, patients' experiences with thiazide prescribing discussions shed light on the facilitators and barriers to implementing clinical practice guidelines regarding thiazides as first-line therapy for hypertension.Trial registrationNational Clinical Trial Registry number NCT00265538

Association between primary care physicians' evidence-based medicine knowledge and quality of care

Ample research has examined physicians' evidence-based medicine (EBM) knowledge and skills; however, previous research has not linked EBM knowledge to objective measures of process of care. A cross-sectional study of quality of care measures extracted from electronic medical records and EBM knowledge assessed via a validated questionnaire. One region of the largest Health Maintenance Organization in Israel. Seventy-four physicians and their 8334 diabetic patients, 7092 coronary heart disease patients and 17 132 hypertensive patients. Outcome measures were four diabetes quality of care indicators (LDL tests, microalbumin tests, hemoglobin A1C tests, eye examination referrals), and two drug prescription indicators (statin prescription for coronary heart disease patients, and thiazide prescription for hypertensive patients). Independent variables were total EBM knowledge and its components: critical appraisal and information retrieval. Total EBM knowledge was independently and significantly associated with LDL testing (b = 0.13; P = 0.036), microalbumin testing (b = 0.33; P = 0.001), hemoglobin A1C testing (b = 0.17; P = 0.036), eye examination referrals (b = 0.16; P = 0.021) and statin prescriptions (b = 0.18; P = 0.025). Critical appraisal was independently associated with microalbumin tests (b = 0.46; P = 0.002) and eye examination referrals (b = 0.20; P = 0.048). Information retrieval was only independently associated with hemoglobin A1C testing (b = 0.43; P = 0.004). Thiazide prescription was not associated with EBM knowledge scores. Physicians' higher total EBM knowledge primarily correlates with better quality of care; however, correlations were modest and explained only a small portion in the variance of clinical performance. Results indicate that there might be a need to focus on teaching all the components of EBM rather than EBM microskills.

Testing a TheoRY-inspired MEssage ('TRY-ME'): a sub-trial within the Ontario Printed Educational Message (OPEM) trial

BackgroundA challenge for implementation researchers is to develop principles that could generate testable hypotheses that apply across a range of clinical contexts, thus leading to generalisability of findings. Such principles may be provided by systematically developed theories. The opportunity has arisen to test some of these theoretical principles in the Ontario Printed Educational Materials (OPEM) trial by conducting a sub-trial within the existing trial structure. OPEM is a large factorial cluster-randomised trial evaluating the effects of short directive and long discursive educational messages embedded into informed, an evidence-based newsletter produced in Canada by the Institute for Clinical Evaluative Sciences (ICES) and mailed to all primary care physicians in Ontario. The content of educational messages in the sub-trial will be constructed using both standard methods and methods inspired by psychological theory. The aim of this study is to test the effectiveness of the TheoRY-inspired MEssage ('TRY-ME') compared with the 'standard' message in changing prescribing behaviour.MethodsThe OPEM trial participants randomised to receive the short directive message attached to the outside of informed (an 'outsert') will be sub-randomised to receive either a standard message or a message informed by the theory of planned behaviour (TPB) using a two (long insert or no insert) by three (theory-based outsert or standard outsert or no outsert) design. The messages will relate to prescription of thiazide diuretics as first line drug treatment for hypertension (described in the accompanying protocol, "The Ontario Printed Educational Materials trial"). The short messages will be developed independently by two research teams.The primary outcome is prescription of thiazide diuretics, measured by routinely collected data available within ICES. The study is designed to answer the question, is there any difference in guideline adherence (i.e., thiazide prescription rates) between physicians in the six groups? A process evaluation survey instrument based on the TPB will be administered pre- and post-intervention (described in the accompanying protocol, "Looking inside the black box"). The second research question concerns processes that may underlie observed differences in prescribing behaviour. We expect that effects of the messages on prescribing behaviour will be mediated through changes in physicians' cognitions.Trial registration numberCurrent controlled trial ISRCTN72772651

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

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.

A quasi-experimental test of an intervention to increase the use of thiazide-based treatment regimens for people with hypertension

BackgroundDespite recent high-quality evidence for their cost-effectiveness, thiazides are underused for controlling hypertension. The goal of this study was to design and test a practice-based intervention aimed at increasing the use of thiazide-based antihypertensive regimens.MethodsThis quasi-experimental study was carried out in general medicine ambulatory practices of a large, academically-affiliated Veterans Affairs hospital. The intervention group consisted of the practitioners (13 staff and 215 trainees), nurses, and patients (3,502) of the teaching practice; non-randomized concurrent controls were the practitioners (31 providers) and patients (18,292) of the non-teaching practices. Design of the implementation intervention was based on Rogers' Diffusion of Innovations model. Over 10.5 months, intervention teams met weekly or biweekly and developed and disseminated informational materials among themselves and to trainees, patients, and administrators. These teams also reviewed summary electronic-medical-record data on thiazide use and blood pressure (BP) goal attainment. Outcome measures were the proportion of hypertensive patients prescribed a thiazide-based regimen, and the proportion of hypertensive patients attaining BP goals regardless of regimen. Thirty-three months of time-series data were available; statistical process control charts, change point analyses, and before-after analyses were used to estimate the intervention's effects.ResultsBaseline use of thiazides and rates of BP control were higher in the intervention group than controls. During the intervention, thiazide use and BP control increased in both groups, but changes occurred earlier in the intervention group, and primary change points were observed only in the intervention group. Overall, the pre-post intervention difference in proportion of patients prescribed thiazides was greater in intervention patients (0.091 vs. 0.058; p = 0.0092), as was the proportion achieving BP goals (0.092 vs. 0.044; p = 0.0005). At the end of the implementation period, 41.4% of intervention patients were prescribed thiazides vs. 30.6% of controls (p < 0.001); 51.6% of intervention patients had achieved BP goals vs. 44.3% of controls (p < 0.001).ConclusionThis multi-faceted intervention appears to have resulted in modest improvements in thiazide prescribing and BP control. The study also demonstrates the value of electronic medical records for implementation research, how Rogers' model can be used to design and launch an implementation strategy, and how all members of a clinical microsystem can be involved in an implementation effort.

Changes in Antihypertensive Prescribing During US Outpatient Visits for Uncomplicated Hypertension Between 1993 and 2004

Monitoring national patterns of antihypertensive drug therapy is essential to assessing adherence to treatment guidelines and the impact of major scientific publications on physician prescribing. We analyzed data from 2 US National Ambulatory Care Surveys to examine trends between 1993 and 2004 in the prescription of antihypertensive drug classes for uncomplicated hypertension and the association between thiazide and beta-blocker prescribing and physician and patient characteristics. Diuretic prescriptions remained level through 2001 (39%; 95% CI: 34% to 44%) but increased to 53% (48% to 58%) in 2003, largely because of a 72% increase in thiazide prescriptions in the first quarter of 2003 (50%; 95% CI: 40% to 59%). However, these increases did not sustain in 2004. Beta-blocker prescriptions increased modestly from 1993 (24%; 95% CI: 19% to 29%) to 2004 (33%; 95% CI: 28% to 39%). Prescription of calcium channel blockers and angiotensin-converting enzyme inhibitors declined significantly following the sixth Joint National Committee report, but both subsequently rebounded to prereport levels. Prescription of angiotensin II receptor blockers increased continuously from 1% in 1995 to 23% by 2004. Polytherapy prescriptions, particularly those involving > or = 3 drug classes, became increasingly prevalent, accounting for 60% of antihypertensive drug visits by 2004. Prescriptions of thiazides and beta-blockers were both more likely in 1998-2004 (versus 1993-1997). Blacks, women, and hospital outpatients were more likely to receive thiazides. Also, cardiologists were more likely to prescribe beta-blockers. Evidence-based guidelines for antihypertensive drug therapy do impact physician prescribing, but the impact seems to be short lived. Future interventions are imperative for promoting long-term adherence to published guidelines.

Authors' Response to Gowdy

We thank A. D. Gowdy for his comments [1] on our article [2]. He suggests that the National Health Service and other health-care providers have a lot to learn from the pharmaceutical industry. Where is the evidence? We are not aware of data that convincingly demonstrate the impact of outreach visits by pharmaceutical representatives. Gowdy indicates that such information exists (“Progress is tracked meticulously”). We would very much like to see it! We have had informal discussions with executives from companies in Norway, and we have been struck by how they themselves question the effectiveness of their marketing strategies. At a recent conference in Denmark, the medical director of a major pharmaceutical company gave a talk on the impact of industry marketing on prescribing habits [3]. He had no other data to show than a handful of anecdotes, and when questioned about this he insisted that neither he nor his marketing department was aware of more rigorous evaluations. The degree of interaction between the pharmaceutical industry and the medical profession is associated with differences in prescribing patterns [4]. Thus, what the pharmaceutical industry is doing in terms of marketing does seem to work, at least to some extent. However, the marketing effort made by industry is massive and includes a wide range of interventions. It is difficult to know what the relative merit of each component is. Even more difficult to estimate is the cost-effectiveness of various marketing strategies. Considering that the pharmaceutical industry spends a five-digit amount ($US) per doctor per year on marketing alone [4], the industry should achieve substantial effects to compare favourably with, for instance, our results: We spent $US500 per doctor and achieved a doubling of thiazide prescriptions [5]. The only study cited by Gowdy did indeed show promising results. However, changes in prescribing were compared between practices that chose to participate in the programme and practices that chose not to [6], and whether this is a fair comparison is uncertain. Moreover, he does not put this study into the context of a systematic review of the relevant research. Gowdy thinks our intervention sounds like “a policing approach”. This does not fit with our perception. The doctors were satisfied with the chance of meeting an industry-independent source of information and appreciated the opportunity to reflect on their own practice in light of the information and feedback that we provided them. Gowdy’s use of the term “evidence-based” when describing the messages conveyed by pharmaceutical companies begs a brief comment. Several investigators have assessed the quality of advertisements and promotional material distributed by the pharmaceutical industry. They consistently conclude with a word of caution against basing clinical practice on claims made by pharmaceutical companies [7–10].

Rational Prescribing in Primary care (RaPP): process evaluation of an intervention to improve prescribing of antihypertensive and cholesterol-lowering drugs.

BackgroundA randomised trial of a multifaceted intervention for improving adherence to clinical practice guidelines for the pharmacological management of hypertension and hypercholesterolemia increased prescribing of thiazides, butdetected no impact onthe use of cardiovascular risk assessment toolsor achievement of treatment targets. We carried out a predominantly quantitative process evaluation to help explain and interpret the trial-findings.MethodsSeveral data-sources were used including: questionnaires completed by pharmacists immediately after educational outreach visits, semi-structured interviews with physicians subjected to the intervention, and data extracted from their electronic medical records. Multivariate regression analyses were conducted to explore the association between possible explanatory variables and the observed variation across practices for the three main outcomes.ResultsThe attendance rate during the educational sessions in each practice was high; few problems were reported, and the physicians were perceived as being largely supportive of the recommendations we promoted, except for some scepticism regarding the use of thiazides as first-line antihypertensive medication. Multivariate regression models could explain only a small part of the observed variation across practices and across trial-outcomes, and key factors that might explain the observed variation in adherence to the recommendations across practices were not identified.ConclusionThis study did not provide compelling explanations for the trial results. Possible reasons for this include a lack of statistical power and failure to include potential explanatory variables in our analyses, particularly organisational factors. More use of qualitative research methods in the course of the trial could have improved our understanding.

Measurement of changes in antihypertensive drug utilisation following primary care educational interventions

To measure changes in drug utilisation following a national general practice education program aimed at improving prescribing for hypertension. A series of nationally implemented, multifaceted educational interventions using social marketing principles focusing on prescribing for hypertension, was commenced in October 1999, and repeated in September 2001 and August 2003. The target group was all primary care prescribers in Australia and interventions were both active (voluntary) and passive. Newsletter and prescribing feedback was mailed in October 1999, September 2001 (newsletter only) and August 2003. Approximately a third of general practitioners (GPs) in Australia undertook at least one active educational activity (clinical audit, educational visit or case study) during the period October 1999-April 2004. National dispensing data from 1996 to 2004 were analysed using time series methodology with a decay term for intervention effect, to assess trends in prescribing of various classes of antihypertensives. In particular, the program aimed to increase the prescribing of thiazide diuretics and beta blockers. Consistent with key intervention messages, the program achieved an increase in low-dose thiazide and beta blocker prescribing. The rate of prescribing of low-dose thiazides doubled from 1.1 per 1000 consultations in October 1999 to 2.4 per 1000 in October 2003. Beta-blocker utilisation showed a more modest but significant increase over the time of the study, with the change in observed versus expected rate of prescribing increasing by 8% by April 2004. Therapeutic options for treating hypertension changed markedly in the time of the study with the advent of ACE inhibitor/Angiotensin II receptor antagonists and thiazide combination products. It is important, therefore, to interpret the results in light of these changes. A national education program aimed at GPs was successful in improving prescribing for hypertension. Lessons learned will be applied in evaluation of future NPS programs and are also applicable to analysis of other interventions aimed at influencing prescribing behaviour.

First-Line First? Trends in Thiazide Prescribing for Hypertensive Seniors

BackgroundEvidence of reduced cardiovascular morbidity and mortality as well as cost support thiazide diuretics as the first-line choice for treatment of hypertension. The purpose of this study was to determine the proportion of senior hypertensives that received thiazide diuretics as first-line treatment, and to determine if cardiovascular and other potentially relevant comorbidities predict the choice of first-line therapy.Methods and FindingsBritish Columbia PharmaCare data were used to determine the cohort of seniors (residents aged 65 or older) who received their first reimbursed hypertension drug during the period 1993 to 2000. These individual records were linked to medical and hospital claims data using the British Columbia Linked Health Database to find the subset that had diagnoses indicating the presence of hypertension as well as cardiovascular and other relevant comorbidities. Rates of first-line thiazide prescribing as proportion of all first-line treatment were analysed, accounting for patient age, sex, overall clinical complexity, and potentially relevant comorbidities. For the period 1993 to 2000, 82,824 seniors who had diagnoses of hypertension were identified as new users of hypertension drugs. The overall rate at which thiazides were used as first-line treatment varied from 38% among senior hypertensives without any potentially relevant comorbidity to 9% among hypertensives with previous acute myocardial infarction. The rate of first-line thiazide diuretic prescribing for patients with and without potentially relevant comorbidities increased over the study period. Women were more likely than men, and older patients were more likely than younger, to receive first-line thiazide therapy.ConclusionsFindings indicate that first-line prescribing practices for hypertension are not consistent with the evidence from randomized control trials measuring morbidity and mortality. The health and financial cost of not selecting the most effective and least costly therapeutic options are significant.

First-Line First? Trends in Thiazide Prescribing for Hypertensive Seniors

First-Line First? Trends in Thiazide Prescribing for Hypertensive Seniors

The potential savings of using thiazides as the first choice antihypertensive drug: cost-minimisation analysis

BackgroundAll clinical practice guidelines recommend thiazides as a first-choice drug for the management of uncomplicated hypertension. Thiazides are also the lowest priced antihypertensive drugs. Despite this, the use of thiazides is much lower than that of other drug-classes. We wanted to estimate the potential for savings if thiazides were used as the first choice drug for the management of uncomplicated hypertension.MethodsFor six countries (Canada, France, Germany, Norway, the UK and the US) we estimated the number of people that are being treated for hypertension, and the proportion of them that are suitable candidates for thiazide-therapy. By comparing this estimate with thiazide prescribing, we calculated the number of people that could switch from more expensive medication to thiazides. This enabled us to estimate the potential drug-cost savings. The analysis was based on findings from epidemiological studies and drug trials, and data on sales and prescribing provided by IMS for the year 2000.ResultsFor Canada, France, Germany, Norway, the UK and the US the estimated potential annual savings were US$13.8 million, US$37.4 million, US$72.2 million, US$10.7 million, US$119.7 million and US$433.6 million, respectively.ConclusionsMillions of dollars could be saved each year if thiazides were prescribed for hypertension in place of more expensive drugs. Our calculations are based on conservative assumptions. The potential for savings is likely considerably higher and may be more than US$1 billion per year in the US.

Injuries. Thiazide diuretics and the risk of hip fracture among 70-79 year old women treated for hypertension

A possible protective effect of thiazide diuretics against the risk of hip fracture was investigated in a case-control study among 70-79 year old women who had been continuously treated with anti-hypertensive drugs for at least 5 years. In 1992, 2 independent national random samples of general practitioners and internists from West Germany identified 311 cases, who had suffered from their first hip fracture in 1991 or 1992 and 414 controls without any fracture of the hip. Besides relevant information about personal characteristics and medical conditions, the physicians provided detailed documentation of all drug prescriptions between 1986 and 1992 using patient records. Odds ratios (adjusted ORs) with 95% confidence intervals (95% Cl) for the association between hip fracture and prescription of thiazides were adjusted for putative confounders such as age, body mass index, smoking habits, alcohol consumption and relevant medical conditions. For prescriptions of any thiazide diuretics for at least 2 consecutive quarters during the period 1986-1990 the adjusted odds ratio was 0.93 (95% Cl: 0.65-1.34). The OR was lower for drugs containing pure thiazides (adjusted OR = 0.74, 95% Cl: 0.33-1.67), but the risk reduction was not statistically significant. For drugs containing thiazides in combination with other agents the adjusted OR was 0.97 (95% Cl: 0.66-1.42). There was no significant association between the duration or cumulative doses of thiazide prescriptions and the risk of hip fracture. In conclusion, these data provide only little evidence, if any, of a protective effect of thiazide diuretics against the risk of hip fracture among 70-79 year old women treated for hypertension.