Petra Denig

How physicians choose drugs.

A drug choice model which includes the physicians attitudes, norms and personal experiences with drugs, was tested. One hundred and sixty-nine physicians were asked to estimate the models components for the treatment of irritable bowel syndrome (IBS) and of renal colic. Given three drugs for both indications, the physicians gave their expectancies about the treatment outcomes, professional acceptability, patient demand and their personal experiences with the drugs. They also stated the value they assign to each of these components when choosing a drug for IBS and for renal colic. The influence of patient demand on the choice of a specific drug appeared to be negligible. The combined effect of the other three elements of the model predicted the stated drug of first choice correctly in 74% (for IBS) and 78% (for renal colic) of the cases, but further analysis showed that only the drug choices for renal colic were as reasoned as the model assumed. Expectancies and values about treatment outcomes determined the drug choice only in part. For choosing a drug for renal colic, the professional environment was more important. Moreover it was found that drug preferences were more related to expectancies about efficacy than to expectancies about side effects for both disorders. The findings can be useful when trying to change prescribing behaviour. Only a limited effect can be expected from the provision of technical drug information. Especially information about costs is unlikely to change prescribing easily, unless values and norms are changed as well. The importance of the professional environment implies that educational programmes in groups might be more effective than individual approaches.

Comparison of various measures for assessing medication refill adherence using prescription data

Several measures using prescription data have been developed for estimating medication refill adherence. Few studies have made direct comparisons, and little is known about the accuracy of these measures in patients on a multiple‐drug regimen.

THERAPEUTIC DECISION-MAKING OF PHYSICIANS

In this review the therapeutic decision-making process of physicians is described. This process is divided into two steps: the generation of a limited set of possible options (the ‘evoked set’) and the selection from this evoked set of a treatment for a specific patient. Factors that are important in both steps are reviewed. Behavioural and decision-making theories in general and decision-making analysis of physicians in particular are discussed to identify possible shortcomings in their decision-making process. Based on this information a model of the drug choice process is presented. With reference to this model possible ways of influencing drug choices of physicians are discussed.

Improving drug treatment in general practice

In the international Drug Education Project, an educational program involving auditing and feedback in peer groups to improve the treatment of asthma and urinary tract infections (UTI) was developed and tested in primary care. Individualized feedback was provided and discussed in 24 Dutch peer groups showing doctors their prescribing practices and underlying reasons for treatment. A parallel, randomized controlled design was used to test the effect on competence and actual prescribing; in one study arm doctors received feedback on asthma treatment and in the other on UTI treatment. Especially the messages to treat asthma exacerbations with oral corticosteroids (17% increase) and to prescribe short courses for UTI (decrease duration of 1.8 days) brought about large improvements. Both messages concerned acute situations, and were clear and relatively easy for GPs to implement. GPs will experience more barriers when changing maintenance treatment of an asthma patient, which could explain the more limited success of this part of the educational program: the proportion of patients treated with inhaled corticosteroids increased 5%. A ceiling effect was experienced regarding drug choice for UTI.

Scope and nature of prescribing decisions made by general practitioners

Background: This study describes cognitive processes of doctors who are deciding on the treatment for a patient. This helps to uncover how prescribing decisions could benefit from (computerised) support. Methods: While thinking aloud, 61 general practitioners made prescribing decisions for five patients with urinary tract infections or stomach complaints. The resulting 305 transcripts were analysed to determine the scope and nature of the decision processes. Differences in the process were related to case or doctor characteristics, and to differences in the quality of prescribing behaviour. Results: The decision processes were not extensive, particularly for patients with a urinary tract infection. The doctors did not actively consider all possible relevant information. Considerations referring to core aspects of the treatment were made in 159 cases (52%) and to contextual aspects in 111 cases (36%). Habitual behaviour, defined as making a treatment decision without any specific contemplation, was observed in 118 cases (40%) and resulted in prescribing first choice as well as second choice drugs. For stomach complaints, second choice drugs were often prescribed after considering other treatments or in view of specific circumstances. Experience of the doctor was not related to the type of decision process. Conclusions: The processes observed deviate from the decision theoretic norm of thoroughly evaluating all possible options, but these deviations do not always result in suboptimal prescribing. Decision support is useful for bringing pertinent information and first choice treatments to the prescribers attention. In particular, information about relevant contraindications, interactions, and costs could improve the quality of prescribing.

Primary prevention of major cardiovascular and cerebrovascular events with statins in diabetic patients : a meta-analysis

BackgroundPatients with diabetes mellitus are at increased risk of developing cardiovascular disease. Controlling lipid levels has a preventive effect on the occurrence of major cardiovascular and cerebrovascular events. Individual trials have shown varying data on the efficacy of treatment with lipid-lowering statin therapy in the primary prevention of such events in diabetes.ObjectiveThe objective of this study was to assess the efficacy of statins in the primary prevention of the first-time occurrence of a major cardiovascular or cerebrovascular event in diabetic patients. Secondary endpoints were fatal/non-fatal stroke, fatal/non-fatal myocardial infarction and all-cause mortality.MethodsA systematic search for trial reports was conducted in PubMed, EMBASE, The Cochrane library and clinicaltrials.gov for the years 1966–2011. Reference lists of reviews and meta-analyses of related subjects were searched. High-quality, randomized, double-blinded clinical trials comparing a statin with placebo for the primary prevention of major cardiovascular and cerebrovascular events in diabetic patients were selected. Only large studies with a minimum of 500 diabetic participants followed-up for at least 2 years were included. Endpoints were major cardiovascular and cerebrovascular events.Trial and patient characteristics were extracted by three researchers. The quality of the included studies was tested with the Jadad score. The combined effect on primary as well as secondary endpoints was measured with a fixed-effect model. Publication bias was examined with a funnel plot.ResultsFour trials were included, for a total of 10 187 participants. Treatment with statins in the primary prevention of major cardiovascular and cerebrovascular events in diabetic patients resulted in a significant relative risk (RR) reduction in the first-time occurrence of major cardiovascular or cerebrovascular events (RR 0.75, 95% CI 0.67–0.85), fatal/non-fatal stroke (RR 0.69, 95% CI 0.51–0.92) and fatal/non-fatal myocardial infarction (RR 0.70, 95% CI 0.54–0.90) and a non-significant RR reduction in all-cause mortality (RR 0.84, 95% CI 0.65–1.09). Among the studies there was non-significant heterogeneity in the individual effect estimates and no publication bias.LimitationsExclusion criteria and endpoints varied slightly between studies. The type and dosing of statin therapy differed between studies. Non-compliance in the statin treatment group and the use of statin treatment in the placebo group could have led to lower risk reductions.ConclusionTreatment with statins in primary prevention among diabetic patients has a significant beneficial effect on event rates of the first-time occurrence of a major cardiovascular or cerebrovascular event, fatal/non-fatal stroke and fatal/non-fatal myocardial infarction. There was a non-significant RR reduction in all-cause mortality.

Review: Relation Between Quality-of-Care Indicators for Diabetes and Patient Outcomes: A Systematic Literature Review

The authors conducted a systematic literature review to assess whether quality indicators for diabetes care are related to patient outcomes. Twenty-four studies were included that formally tested this relationship. Quality indicators focusing on structure or processes of care were included. Descriptive analyses were conducted on the associations found, differentiating for study quality and level of analysis. Structure indicators were mostly tested in studies with weak designs, showing no associations with surrogate outcomes or mixed results. Process indicators focusing on intensification of drug treatment were significantly associated with better surrogate outcomes in three high-quality studies. Process indicators measuring numbers of tests or visits conducted showed mostly negative results in four high-quality studies on surrogate and hard outcomes. Studies performed on different levels of analysis and studies of lower quality gave similar results. For many widely used quality indicators, there is insufficient evidence that they are predictive of better patient outcomes.

IMPACT OF A DRUG BULLETIN ON THE KNOWLEDGE, PERCEPTION OF DRUG UTILITY, AND PRESCRIBING BEHAVIOR OF PHYSICIANS

The impact of a drug bulletin was tested in a randomized controlled trial that included 186 family physicians. The length of the trial was six months. It was hypothesized that printed information, such as in drug bulletins, influences physician prescribing behavior by changing their knowledge of drug efficacy and adverse effects and their perceptions of drug utility. Therefore, the impact of a drug bulletin was evaluated on these domains of influence. Interview data were used to assess changes in knowledge, perceived drug utility, and stated prescribing. Health insurance funds’ records were used to collect actual prescribing data. Information in the bulletin on the treatment of renal colic changed physicians’ knowledge as well as perceived utility of drugs used for renal colic (p<0.05). Significant changes in stated prescribing were also found. On the other hand, advice in the same bulletin on the treatment of the irritable bowel syndrome (IBS) had no impact at all. It did not even improve the knowledge of the physicians about the drugs used for IBS. Apparently, the message about the treatment of IBS failed to gain the attention of the physicians. It is suggested that some messages are sufficiently transmitted through written information, and others that are seen as less relevant or too difficult to implement need more intensive strategies.

A longitudinal study examining adherence to guidelines in diabetes care according to different definitions of adequacy and timeliness

Background Performance indicators assessing quality of diabetes care often look at single processes, e.g. whether an HbA1c test was conducted. Adequate care, however, consists of consecutive processes which should be taken in time (clinical pathways). We assessed quality of diabetes care by looking at single processes versus clinical pathways. In addition, we evaluated the impact of time period definitions on this quality assessment. Methodology We conducted a cohort study in 2007–2008 using the GIANTT (Groningen Initiative to Analyse type 2 diabetes Treatment) database. Proportions of patients adequately managed for HbA1c, systolic blood pressure (SBP), LDL-cholesterol (LDL-C), and albumin/creatinin ratio (ACR) were calculated for the pathway of (1) risk factor level testing, (2) treatment intensification when indicated, (3) response to treatment evaluation. Strict and wide time periods for each step were defined. Proportions of patients adequately managed regarding the overall pathway and single steps, using strict or wide time periods were compared using odds ratios (OR) with 95% confidence intervals. Findings Of 11176 patients diagnosed with type 2 diabetes, 9439 with complete follow-up were included. The majority received annual examination of HbA1c (86%) and SBP (86%), whereas this was 67% for LDL-C and 49% for ACR. Adequate management regarding the three-step pathway was observed in 73%, 53%, 46%, 41% of patients for HbA1c, SBP, LDL-C, and ACR respectively. Quality scores reduced significantly due to the second step (OR 0.43, 0.18, 0.44, 0.74), but were not much further reduced by the third step. Timely treatment evaluation occurred in 88% for HbA1c, 87% for SBP, 83% for LDL-C, and 76% for ACR. The overall score was not significantly changed by using strict time windows. Conclusion Quality estimates of glycemic, blood pressure and cholesterol management are substantially reduced when looking at clinical pathways as compared to estimates based on commonly used simple process measures.

Effects of a patient oriented decision aid for prioritising treatment goals in diabetes: pragmatic randomised controlled trial.

Objective To assess the effects of a patient oriented decision aid for prioritising treatment goals in diabetes compared with usual care on patient empowerment and treatment decisions. Design Pragmatic randomised controlled trial. Setting 18 general practices in the north of the Netherlands. Participants 344 patients with type 2 diabetes aged ≤65 years at the time of diagnosis and managed in primary care between April 2011 and August 2012: 225 were allocated to the intervention group and 119 to the usual care group. Intervention The intervention comprised a decision aid for people with diabetes, with individually tailored risk information and treatment options for multiple risk factors. The aid was intended to empower patients to prioritise between clinical domains and to support treatment decisions. It was offered to participants before a regular diabetes check-up and to their healthcare provider during the consultation. Four different formats of the decision aid were included for additional explorative analyses. Main outcome measures The primary outcome was the effects on patient empowerment for setting and achieving goals. The secondary outcomes were changes in the prescribing of drugs to regulate glucose, blood pressure, lipids, and albuminuria. Data were collected through structured questionnaires and automated data extraction from electronic health records during six months before and after the intervention. Results Of all intervention participants, 103 (46%) reported to have received the basic elements of the intervention. For the primary outcome analysis, 199 intervention and 107 control patients with sufficient baseline and follow-up data could be included. The mean empowerment score increased 0.1 on a 5 point scale in the overall intervention group, which was not significantly different from that of the control group (mean difference after adjusting for baseline 0.039, 95% confidence interval −0.056 to 0.134). Lipid regulating drug treatment was intensified in 25% of intervention and 12% of control participants with increased cholesterol levels, which did not reach significance when the intervention was compared with the usual care group (odds ratio 2.54, 95% confidence interval 0.89 to 7.23). Prespecified explorative analyses showed that this effect was significant for the printed version of the decision aid in comparison to usual care (3.90, 1.29 to 11.80). No relevant or significant changes were seen for other treatments. Conclusion We found no evidence that the patient oriented treatment decision aid improves patient empowerment by an important amount. The aid was not used to its full extent in a substantial number of participants. Trial registration Dutch trial register NTR1942.