Determinants of the range of drugs prescribed in general practice: a cross-sectional analysis

Factors Influencing Prescribing Perceived Utility of Drugs: Experiences from Iraqi Kurdistan

INTRODUCTION

Pharmaceutical expenditures have increased dramatically in most developed and developing countries in recent decades. Healthcare system policymakers have expressed concerns about the inappropriate, irrational, or harmful prescribing of drugs.

OBJECTIVES

The attitudes of physicians towards prescribing generic drugs and predictors of perceived utility of drugs were investigated in the present study.

METHODS

In this cross-sectional research, 77 physicians at different levels of job hierarchies, working in various public sector shifts, were recruited to participate in a survey of their attitudes toward prescribing generic drugs in Iraqi Kurdistan in 2018. The doctors were located in a general, an emergency, and a pediatric hospital. A self-administered structured questionnaire was designed based on the extended technology acceptance model for product use (TETPU).

RESULTS

The doctors agreed that drugs should be prescribed according to their utility for patients (median [M] = 5.0; interquartile range [IQR] = 2.9). Most of the physicians mentioned that they prescribed drugs according to the patients' needs (75.0%), evaluation of the availability of alternatives (69.0%) and consumer perceptions of a price (69.0%). The analysis showed that (1) the importance of physicians' perceptions and their recognition of patients' need achievement (P=.012), (2) the physicians' recognition of the actual use of drugs by consumers (P=.030) and (3) being male (p=.009) were associated with perceptions of drug utility.

CONCLUSIONS

The study's results suggest that perceived drug utility in prescription writing is associated with physicians' perceptions of need achievement and attitudes toward how patients actually use medicines.

The influential role of personal advice networks on general practitioners' performance: a social capital perspective

Background

In several health systems of advanced countries, reforms have changed primary care in the last two decades. The literature has assessed the effects of a variety of interventions and individual factors on the behavior of general practitioners (GPs). However, there has been a lack of investigation concerning the influence of the resources embedded in the GPs’ personal advice networks (i.e., social capital) on GPs’ capacity to meet defined objectives.

The present study has two goals: (a) to assess the GPs’ personal advice networks according to the social capital framework and (b) to test the influence of such relationships on GPs’ capacity to accomplish organizational goals.

Methods

The data collection relied on administrative data provided by an Italian local health authority (LHA) and a survey administered to the GPs of the selected LHA. The GPs’ personal advice networks were assessed through an ad-hoc instrument and interpreted as egocentric networks. Multivariate regression analyses assessed two different performance measures.

Results

Social capital may influence the GPs’ capacity to meet targets, though the influence differs according to the objective considered. In particular, the higher the professional heterogeneity of a GP personal advice network, the lower her/his capacity is to meet targets of prescriptive appropriateness.

Conclusions

Our findings might help to design more effective primary care reforms depending on the pursued goals. However, further research is needed.

Addressing ethical challenges at the intersection of pharmacogenomics and primary care using deliberative consultations

AIM

Primary care physicians will play a central role in the successful implementation of pharmacogenomics (PGx); however, important challenges remain. We explored the perspectives of stakeholders on key challenges of the PGx translation process in primary care using deliberative consultations.

METHODS

Primary care physicians, patients and policy-makers attended deliberations, where they discussed four ethical questions raised by PGx research and implementation in the primary care context.

RESULTS

Stakeholders voiced skepticism regarding PGx funding, commercialization, regulation, maintenance of an equal access healthcare system and restructuring of health research incentives and priorities in the public sector.

CONCLUSION

Deliberants developed governing principles for a PGx-specific charter of ethics, aiming to protect the interests of patients, and outlined recommendations for the future of PGx in primary care.

Reducing antibiotic prescriptions for respiratory tract infections in family practice: results of a cluster randomized controlled trial evaluating a multifaceted peer-group-based intervention

Irrational antibiotic use for respiratory tract infections (RTI) is a major driver of bacterial resistance. The aim of this study was to evaluate the effect of a multifaceted peer-group based intervention aiming to reduce RTI-related antibiotic prescriptions in family practice. This was a cluster randomized controlled trial with pre- and follow-up measurement. The intervention was implemented through PharmacoTherapy Audit Meetings (PTAM) in which family physicians (FPs) and pharmacists collaborate. Four PTAM groups received the intervention consisting of: (1) FP communication skills training, including communication about delayed prescribing; (2) implementation of antibiotic prescribing agreements in FPs’ Electronic Prescribing Systems; (3) quarterly feedback figures for FPs. Four other PTAM groups were matched controls. Primary outcome measure was the number of RTI-related antibiotic prescriptions after the intervention, assessed with multilevel linear regression analyses. Total number and number of prescriptions stratified by age (under/over 12 years) were analysed. At baseline, the average total number of RTI-related antibiotic prescriptions per 1,000 patients was 207.9 and 176.7 in the intervention and control PTAM groups, respectively. At follow-up, FPs in both the intervention and control groups prescribed significantly less antibiotics. For adolescents and adults, the drop in number of antibiotic prescription was significantly larger in the intervention groups (−27.8 per 1,000 patients) than the control groups (−7.2 per 1,000 patients; P<0.05). This multifaceted peer-group-based intervention was effective in reducing the number of RTI-related antibiotic prescriptions for adolescents and adults. To affect antibiotic prescribing in children other methods are needed.

General Practitioners' intention to prescribe and prescribing patterns in selected European settings: The OTCSOCIOMED project

The aim of this paper is to explore general practitioners' (GPs) prescribing intentions and patterns across different European regions using the Theory of Planned Behavior (TPB). A cross-sectional study was undertaken in selected geographically defined Primary Health Care areas in Cyprus, Czech Republic (CZ), France, Greece, Malta, Sweden and Turkey. Face-to-face interviews were conducted using a TPB-based questionnaire. The number of GP participants ranged from 39 to 145 per country. Possible associations between TPB direct measures (attitudes, subjective norms (SN) and perceived behavioral control (PBC)) and intention to prescribe were assessed by country. On average, GPs thought positively of, and claimed to be in control of, prescribing. Correlations between TPB explanatory measures and prescribing intention were weak, with TPB direct measures explaining about 25% of the variance in intention to prescribe in Malta and CZ but only between 3% and 5% in Greece, Sweden and Turkey. SN appeared influential in GPs from Malta; attitude and PBC were statistically significant in GPs from CZ. GPs' prescribing intentions and patterns differed across participating countries, indicating that country-specific interventions are likely to be appropriate. Irrational prescribing behaviors were more apparent in the countries where an integrated primary care system has still not been fully developed and policies promoting the rational use of medicines are lacking. Demand-side measures aimed at modifying GPs prescribing behavior are deemed necessary.

Factors affecting family physicians' drug prescribing: a cross-sectional study in Khuzestan, Iran

BACKGROUND

Rational prescription is a considerable issue which must be paid more attention to assess the behavior of prescribers. The aim of this study was to examine factors affecting family physicians' drug prescribing.

METHODS

We carried out a retrospective cross-sectional study in Khuzestan province, Iran in 2011. Nine hundred eighty-six prescriptions of 421 family physicians (including 324 urban and 97 rural family physicians) were selected randomly. A multivariate Poisson regression was used to investigate potential determinants of the number of prescribed drug per patient.

RESULTS

The mean of medication per patient was 2.6 ± 1.2 items. In the majority (91.9%) of visits a drugs was prescribed. The most frequent dosage forms were tablets, syrups and injection in 30.1%, 26.9%, and 18.7% of cases respectively. Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) and antibiotics were 29.7% and 17.1% of prescribed drugs respectively. The tablets were the most frequent dosage forms (38.6% of cases) in adult's patients and syrups were the most frequent dosage forms (49% of cases) in less than 18 years old. Paracetamols were popular form of NSAIDs in two patients groups. The most common prescribed medications were oral form.

CONCLUSION

In Khuzestan, the mean of medication per patient was fewer than national average. Approximately, pattern of prescribed drug by family physicians (including dosage form and type of drugs) was similar to other provinces of Iran.

The future of genomic testing in primary care: the changing face of personalized medicine

Primary care is recognized worldwide as a key component for improving health outcomes in the population. At the same time, healthcare systems are rapidly changing with increasing expectations from technological advances. Genomics is a major driver in changing how medicine is being practiced; however, the importance for primary care has been under-appreciated. Strategically implementing genomics in a way that accounts for the unique characteristics of the primary care context is essential. In this perspective, we present important areas that we believe are critical in consideration of both the future of genomic medicine and primary healthcare delivery.

Changes in physician antipsychotic prescribing preferences, 2002-2007

OBJECTIVE

Physician antipsychotic prescribing behavior may be influenced by comparative effectiveness evidence, regulatory warnings, and formulary and other restrictions on these drugs. This study measured changes in the degree to which physicians are able to customize treatment choices and changes in physician preferences for specific agents after these events.

METHODS

The study used 2002-2007 prescribing data from the IMS Health Xponent database and data on physician characteristics from the American Medical Association for a longitudinal cohort of 7,399 physicians. Descriptive and multivariable regression analyses were conducted of the concentration of prescribing (physician-level Herfindahl index) and preferences for and likelihood of prescribing two first-generation antipsychotics and six second-generation antipsychotics. Analyses adjusted for prescribing volume, specialty, demographic characteristics, practice setting, and education.

RESULTS

Antipsychotic prescribing was highly concentrated at the physician level, with a mean unadjusted Herfindahl index of .33 in 2002 and .29 in 2007. Psychiatrists reduced the concentration of their prescribing more over time than did other physicians. High-volume psychiatrists had a Herfindahl index that was half that of low-volume physicians in other specialties (.18 versus .36), a difference that remained significant (p<.001) after adjustment for physician characteristics. The share of physicians preferring olanzapine dropped from 29.9% in 2002 to 10.3% in 2007 (p<.001) while the share favoring quetiapine increased from 9.4% to 44.5% (p<.001). Few physicians (<5%) preferred a first-generation antipsychotic in 2002 or 2007.

CONCLUSIONS

Preferences for specific antipsychotics changed dramatically during this period. Although physician prescribing remained heavily concentrated, the concentration decreased over time, particularly among psychiatrists.

The assessment of pharmaceutical sales representatives by family physicians--does it affect the prescribing index?

BACKGROUND

Physicians' prescribing patterns depend on fixed and influence-sensitive factors. The latter include the influence of interactions with the pharmaceutical industry.

OBJECTIVE

To determine whether the assessment of pharmaceutical sales representatives (PSRs) by family physicians was associated with their actual prescribing index.

METHODS

Cross-sectional anonymous postal study. We included all family physicians working in practice settings in Slovenia in 2011.

SETTINGS

Slovenian family physicians' surgeries.

MAIN OUTCOME MEASURE

Prescribing index of Slovenian family physicians.

RESULTS

We received 247 responses (27.6% response rate). A prescribing index >100% was present in 57 (23.1%) of the respondents. Multivariate analysis revealed that working in regions of Slovenia other than the central region might be associated with a prescribing index >100%. Assessment of PSRs by family physicians was not significantly associated with a prescribing index >100%.

CONCLUSION

The assessment of PSRs by family physicians does not have any substantial correlations with their prescribing index.

Variation in formulary adherence in general practice over time (2003-2007)

OBJECTIVE

To study trends and variation in adherence to the main national formulary for the 20 most prevalent health problems in Dutch general practice over a 5-year period (2003-07).

METHODS

Routine electronic medical records from a pool of 115 representative general practices were linked to the main national formulary. Analyses included over 2 million prescriptions for 246 391 patients. The outcome variable was whether or not the prescribed medication was congruent with recommendations in the national formulary. Trends and variation were analysed using three-level multilevel logistic regression analyses (general practice, patient, and prescription).

RESULTS

The percentage of formulary adherent prescriptions for the 20 most prevalent health problems was 73-76% between 2003 and 2007. The percentage varied considerably between guidelines. Lowest adherence rates were found for acute bronchitis and acute upper respiratory infection. Interpractice variation was constant over time.

CONCLUSIONS

General practice information networks are useful for monitoring general patterns of formulary on a year-to-year basis. Formulary adherence is stable over time but varies across diagnoses, patients and general practices. In the past decade, efforts have been made to increase the level of formulary adherent prescribing. These general efforts managed to stabilize (variation in) adherence in a field where many other initiatives (e.g. by pharmaceutical companies) are undertaken to influence prescribing behaviour.

Family doctors' views of pharmaceutical sales representatives: assessment scale development

BACKGROUND

The prescribing patterns depend on the physicians' attitudes and their subjective norms towards prescribing a particular drug, as well as on their personal experience with a particular drug. The physicians are affected by their interactions with pharmaceutical industry.

OBJECTIVE

The objectives were to develop a scale for assessment of pharmaceutical sales representatives (PSRs) by the family doctors (FDs) and to determine factors for their evaluation.

METHOD

Cross-sectional anonymous postal study. We included a random sample of 250 Slovenian FDs. Settings. Slovenian FDs' surgeries.

MAIN OUTCOME MEASURE

The score of various items regarding FDs' assessment of PSRs on a 7-point Likert scale.

RESULTS

We got 163 responses (65.2% response rate). The most important characteristic of PSRs, as rated by respondents on the scale from 1 to 7, was the fact that they did not mislead when presenting products' information. The second most important characteristic was the ability to provide objective information about the product. The first three most important characteristics, as rated by the respondents by themselves, were 'Shows good knowledge on the promoted subject', 'Provides objective product information' and 'Makes brief and exact visits'. Cronbach's alpha of the composite scale was 0.844. Factor analysis revealed three PSRs' factors: selling skills, communicating skills and sense of trustworthiness.

CONCLUSION

FDs evaluate PSRs mainly by their managerial skills and trustworthiness. The scale proved to be a reliable tool for assessing PSRs by FDs.

Sources of drug information and their influence on the prescribing behaviour of doctors in a teaching hospital in Ibadan, Nigeria

Background

Pharmaceutical drug promotion is a means of informing health professionals about new drugs. The approach is often times unethical and inappropriate and may promote irrational prescribing. Dearth of information on impact of pharmaceutical drug promotion on prescribing behaviour of doctors in developing African countries has necessitated this study. We therefore aimed to determine the sources of drug information for doctors working in a teaching hospital in Nigeria and to assess the self-reported impact of the sources on their prescribing behaviour.

Methods

A total of 163 doctors working at the University College Hospital (UCH), Ibadan in Nigeria were evaluated with a questionnaire for their demographics and sources of drug information. For doctors who relied on drug promotion, they were asked to self-report and self-rate their opinion on extent of interactions with pharmaceutical companies as well as how such interactions had impacted on their prescribing behaviour. Apart from the demographics, each question was evaluated with a typical five-level Likert item. Data analyses were with simple descriptive statistics.

Results

Of the 400 doctors working at UCH, only 40.8% participated in the study. Drug information was sourced from colleagues (161, 98.8%), reference books (158, 96.9%), pharmaceutical sales representatives-PSRs (152, 93.2%), promotion materials (151, 92.6%), scientific papers/journals/internet (149, 91.4%), and drug promotion forum/product launches (144, 88.3%). Each source was highly utilized but there was no wide variation in their pattern of use. According to the self-report of over a half of the respondents, PSRs was an accurate and reliable drug information resource; PSRs increased their awareness of the promoted drugs; and their prescribing behaviours were influenced by information from PSRs.

Conclusion

Respondents tend to rely on a broad range of drug information resources which include potentially inappropriate resources such as PSRs. Since this study was based on self-report, the influence of drug information resources reported by the respondents on their prescribing behaviour may have been underestimated. Measures should be taken to minimize interactions between PSRs and the respondents.

Information from pharmaceutical companies and the quality, quantity, and cost of physicians' prescribing: a systematic review

BACKGROUND

Pharmaceutical companies spent $57.5 billion on pharmaceutical promotion in the United States in 2004. The industry claims that promotion provides scientific and educational information to physicians. While some evidence indicates that promotion may adversely influence prescribing, physicians hold a wide range of views about pharmaceutical promotion. The objective of this review is to examine the relationship between exposure to information from pharmaceutical companies and the quality, quantity, and cost of physicians' prescribing.

METHODS AND FINDINGS

We searched for studies of physicians with prescribing rights who were exposed to information from pharmaceutical companies (promotional or otherwise). Exposures included pharmaceutical sales representative visits, journal advertisements, attendance at pharmaceutical sponsored meetings, mailed information, prescribing software, and participation in sponsored clinical trials. The outcomes measured were quality, quantity, and cost of physicians' prescribing. We searched Medline (1966 to February 2008), International Pharmaceutical Abstracts (1970 to February 2008), Embase (1997 to February 2008), Current Contents (2001 to 2008), and Central (The Cochrane Library Issue 3, 2007) using the search terms developed with an expert librarian. Additionally, we reviewed reference lists and contacted experts and pharmaceutical companies for information. Randomized and observational studies evaluating information from pharmaceutical companies and measures of physicians' prescribing were independently appraised for methodological quality by two authors. Studies were excluded where insufficient study information precluded appraisal. The full text of 255 articles was retrieved from electronic databases (7,185 studies) and other sources (138 studies). Articles were then excluded because they did not fulfil inclusion criteria (179) or quality appraisal criteria (18), leaving 58 included studies with 87 distinct analyses. Data were extracted independently by two authors and a narrative synthesis performed following the MOOSE guidelines. Of the set of studies examining prescribing quality outcomes, five found associations between exposure to pharmaceutical company information and lower quality prescribing, four did not detect an association, and one found associations with lower and higher quality prescribing. 38 included studies found associations between exposure and higher frequency of prescribing and 13 did not detect an association. Five included studies found evidence for association with higher costs, four found no association, and one found an association with lower costs. The narrative synthesis finding of variable results was supported by a meta-analysis of studies of prescribing frequency that found significant heterogeneity. The observational nature of most included studies is the main limitation of this review.

CONCLUSIONS

With rare exceptions, studies of exposure to information provided directly by pharmaceutical companies have found associations with higher prescribing frequency, higher costs, or lower prescribing quality or have not found significant associations. We did not find evidence of net improvements in prescribing, but the available literature does not exclude the possibility that prescribing may sometimes be improved. Still, we recommend that practitioners follow the precautionary principle and thus avoid exposure to information from pharmaceutical companies. Please see later in the article for the Editors' Summary.

Characteristics of primary health care units with focus on drug information from the pharmaceutical industry and adherence to prescribing objectives: a cross-sectional study

BACKGROUND

Adherence to prescribing guidelines varies between primary health care units. The aim of the present study was to investigate correlations between characteristics of primary health care units and adherence to prescribing objectives for rational drug use with focus on drug information from the pharmaceutical industry.

METHODS

A cross-sectional study was performed in all 25 primary health care units in Göteborg, Sweden. A questionnaire on characteristics of practice settings [(i) size of unit, (ii) profession of head, (iii) use of temporary physicians, (iv) drug information from the pharmaceutical industry, (v) producer-independent drug information, and (vi) education on prescribing for newly employed physicians] was sent to the heads of the units. A national sales register for prescribed drugs (Xplain) was used for evaluation of adherence to the six regional prescribing objectives concerning proton pump inhibitors (PPIs), angiotensin converting enzyme inhibitors (ACEIs), statins and antidepressants.

RESULTS

Twenty-two out of 25 primary health care units responded to the questionnaire (response rate 88%). A physician as head and presence of producer-independent drug information was positively correlated with adherence to the prescribing objectives (median number of prescribing objectives adhered to (25th - 75th percentile): 2.5 (1-3.25) vs 1 (0-2), P = 0.013; 2 (1-3) vs 0, P = 0.043, respectively. Presence of drug information from the pharmaceutical industry and education on prescribing for newly employed physicians was negatively associated with adherence to the prescribing objectives: 1 (0-2) vs 3.5 (2.25-4.75), P = 0.005; 1 (0-2) vs 3 (1.5-4), P = 0.034, respectively.

CONCLUSION

Several characteristics of the primary health care units correlated with adherence to prescribing objectives for rational drug use. Further research on this topic is needed and would constitute valuable information for health care decision makers.

Labour intensity of guidelines may have a greater effect on adherence than GPs' workload

Background

Physicians' heavy workload is often thought to jeopardise the quality of care and to be a barrier to improving quality. The relationship between these has, however, rarely been investigated. In this study quality of care is defined as care 'in accordance with professional guidelines'. In this study we investigated whether GPs with a higher workload adhere less to guidelines than those with a lower workload and whether guideline recommendations that require a greater time investment are less adhered to than those that can save time.

Methods

Data were used from the Second Dutch National survey of General Practice (DNSGP-2). This nationwide study was carried out between April 2000 and January 2002.

A multilevel logistic-regression analysis was conducted of 170,677 decisions made by GPs, referring to 41 Guideline Adherence Indicators (GAIs), which were derived from 32 different guidelines. Data were used from 130 GPs, working in 83 practices with 98,577 patients. GP-characteristics as well as guideline characteristics were used as independent variables. Measures include workload (number of contacts), hours spent on continuing medical education, satisfaction with available time, practice characteristics and patient characteristics. Outcome measure is an indicator score, which is 1 when a decision is in accordance with professional guidelines or 0 when the decision deviates from guidelines.

Results

On average, 66% of the decisions GPs made were in accordance with guidelines. No relationship was found between the objective workload of GPs and their adherence to guidelines. Subjective workload (measured on a five point scale) was negatively related to guideline adherence (OR = 0.95). After controlling for all other variables, the variation between GPs in adherence to guideline recommendations showed a range of less than 10%.

84% of the variation in guideline adherence was located at the GAI-level. Which means that the differences in adherence levels between guidelines are much larger than differences between GPs. Guideline recommendations that require an extra time investment during the same consultation are significantly less adhered to: (OR = 0.46), while those that can save time have much higher adherence levels: OR = 1.55). Recommendations that reduce the likelihood of a follow-up consultation for the same problem are also more often adhered to compared to those that have no influence on this (OR = 3.13).

Conclusion

No significant relationship was found between the objective workload of GPs and adherence to guidelines. However, guideline recommendations that require an extra time investment are significantly less well adhered to while those that can save time are significantly more often adhered to.

Factors influencing prescribing behaviour of physicians in Greece and Cyprus: results from a questionnaire based survey

Background

Over the past few decades, drug and overall healthcare expenditure have risen rapidly in most countries. The present study investigates the attitudes and the factors which influence physician prescribing decisions and practice in Greece and Cyprus.

Methods

A postal questionnaire was developed by researchers at the Department of Health Economics at the National School of Public Health in Greece, specifically for the purposes of the study. This was then administered to a sample of 1,463 physicians in Greece and 240 physicians in Cyprus, stratified by sex, specialty and geographic region.

Results

The response rate was 82.3% in Greece and 80.4% in Cyprus. There were similarities but also many differences between the countries. Clinical effectiveness is the most important factor considered in drug prescription choice in both countries. Greek physicians were significantly more likely to take additional criteria under consideration, such as the drug form and recommended daily dose and the individual patient preferences. The list of main sources of information for physicians includes: peer-reviewed medical journals, medical textbooks, proceedings of conferences and pharmaceutical sales representatives. Only half of prescribers considered the cost carried by their patients. The majority of doctors in both countries agreed that the effectiveness, safety and efficacy of generic drugs may not be excellent but it is acceptable. However, only Cypriot physicians actually prescribe them. Physicians believe that new drugs are not always better and their higher prices are not necessarily justified. Finally, doctors get information regarding adverse drug reactions primarily from the National Organisation for Medicines. However, it is notable that the majority of them do not inform the authorities on such reactions.

Conclusion

The present study highlights the attitudes and the factors influencing physician behaviour in the two countries and may be used for developing policies to improve their choices and hence to increase clinical and economic effectiveness and efficiency.

Do decision support systems influence variation in prescription?

Background

Translating scientific evidence into daily practice is problematic. All kinds of intervention strategies, using educational and/or directive strategies, aimed at modifying behavior, have evolved, but have been found only partially successful. In this article the focus is on (computerized) decision support systems (DSSs). DSSs intervene in physicians' daily routine, as opposed to interventions that aim at influencing knowledge in order to change behavior. We examined whether general practitioners (GPs) are prescribing in accordance with the advice given by the DSS and whether there is less variation in prescription when the DSS is used.

Methods

Data were used from the Second Dutch National Survey of General Practice (DNSGP2), collected in 2001. A total of 82 diagnoses, 749811 contacts, 133 physicians, and 85 practices was included in the analyses. GPs using the DSS daily were compared to GPs who do not use the DSS. Multilevel analyses were used to analyse the data. Two outcome measures were chosen: whether prescription was in accordance with the advice of the DSS or not, and a measure of concentration, the Herfindahl-Hirschman Index (HHI).

Results

GPs who use the DSS daily prescribe more according to the advice given in the DSS than GPs who do not use the DSS. Contradictory to our expectation there was no significant difference between the HHIs for both groups: variation in prescription was comparable.

Conclusion

We studied the use of a DSS for drug prescribing in general practice in the Netherlands. The DSS is based on guidelines developed by the Dutch College of General Practitioners and implemented in the Electronic Medical Systems of the GPs. GPs using the DSS more often prescribe in accordance with the advice given in the DSS compared to GPs not using the DSS. This finding, however, did not mean that variation is lower; variation is the same for GPs using and for GPs not using a DSS. Implications of the study are that DSSs can be used to implement guidelines, but that it should not be expected that variation is limited.