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Biomedical subjects

R A Winkens

Publications and source records attributed to R A Winkens.

18 recordsLinked to original sources
PubMed2001

Validation of a knowledge based reminder system for diagnostic test ordering in general practice.

We describe the validation of a real-time automated reminder system that assists General Practitioners (GP) in appropriate test ordering. We compared the comments of human experts with the comments of the reminder system using a retrospective random selection of 253 request forms. A panel of three expert physicians judged the requested tests independently based on their interpretations of the practice guidelines. The majority assessment of the physicians was compared with the assessment of the reminder system. In case the system's output differed from the majority assessment the written practice guidelines were consulted. On average 1.75 reminders were produced per form. In total 32 of the 442 given reminders (7%) were given incorrectly. The amount of information and the level of detail (the specificity of the terms) in which the GP describes the patients' medical status are crucial for the reminder system to react correctly.

Adult↗
PubMed2001

Reliability of the assessment of appropriateness of diagnostic test request behavior.

We describe the reliability of the assessment of the appropriateness of requested diagnostic tests. We used a retrospective random selection of 253 request forms with in total 1217 requested tests. Three experts made an independent assessment of each requested test. Interrater kappa values ranged from 0.33 to 0.44. The kappa values of intrarater agreement ranged from 0.65 to 0.68. The reliability coefficient for all three reviewers was 0.66. This reliability is not sufficient to make case-by-case decisions, for example to give individual feedback on the appropriateness of requested tests. Sixteen reviewers are necessary to obtain a reference with a reliability of 0.95.

Decision Support Systems, Clinical↗
PubMed2000

A test ordering system with automated reminders for primary care based on practice guidelines.

In this article we describe a real-time automated reminder system that has been developed to change Family Physicians' (FP) test ordering behavior. The system focuses on the appropriateness of test requests. We aim at using the system as a substitute for written feedback by human experts. The reminder system consists of a knowledge base, an order entry system and modules to provide passive and active support in the form of reminders to FPs. The system generates critical comments about the rationality of the test requests at the moment the FP orders a test that is not in line with national or regional guidelines. For the first validation of the knowledge base we compared the comments of a human expert to the comments of the reminder system on three random samples of test requests. The overall agreement in the subsequent validation rounds was 46, 60 and 69%. The corrections made in the knowledge base after each validation round resulted in a reminder system with 149 reminders concerning various medical problems. Due to the corrections in the knowledge base the reminder system reacts better over the subsequent validation rounds.

Diagnostic Tests, Routine↗
PubMed2000

Comparing assessment of appropriateness of diagnostic tests between a human expert and an automated reminder system.

This paper describes the validation of the GRIF automated reminder system. The reminder system has been developed to influence diagnostic test ordering of General Practitioners (GPs). It generates critical comments on the basis of accepted guidelines. A retrospective random selection of 253 request forms has been taken. We compared the comments of a human expert to the comments of the reminder system. A panel of two independent reviewers judged the requested tests based on the strict interpretation of the guidelines. The sensitivity, specificity and 'predictive values' of the comments of the reminder system and the human expert were calculated using the judgement of the two reviewers as 'gold standard'.

Artificial Intelligence↗
PubMed1999

Development of a reminder system for general practitioners.

In this contribution we describe a prototype reminder system that has been developed to influence General Practitioners' (GP) test request behaviour. It is intended to substitute conventional written feedback by human experts. The system generates critical comments about the rationality of the test request at the moment the GP requests a test that is not in line with national or regional guidelines.

Artificial Intelligence↗
PubMed1997

Fitting a routine health-care activity into a randomized trial: an experiment possible without informed consent?

Due to possible methodological and practical problems, many researchers refrain from using a randomized controlled trial design to evaluate procedures already embedded in routine health care. We performed a randomized controlled trial on the effects of routine individual feedback on test ordering behavior of family physicians. The trial started after 4 years of feedback and lasted for 2.5 years. With some adaptations a randomized trial proved to be possible. In evaluating health-care procedures that cannot be blinded in a traditional way, asking full and study-specific informed consent may conflict with the validity of the design. In such studies, an alternative procedure is to be considered. Our trial, with doctors as study subjects, was held on an already accepted routine procedure (feedback). This made it possible to refrain from obtaining study-specific informed consent. Consequently, a Hawthorne effect and contamination of the trial arms through information leakage could be avoided. Justification and general criteria for not obtaining full and study-specific informed consent are worked out. In health-care research on the performance of doctors or on interventions into the quality of care, obtaining a general informed consent in advance is an acceptable alternative approach.

Diagnostic Tests, Routine↗
PubMed1996

Factors predicting differences among general practitioners in test ordering behaviour and in the response to feedback on test requests.

BACKGROUND: In a population of 85 general practitioners diagnostic test ordering behaviour has been changed by means of repeated individual feedback provided since 1985. OBJECTIVES: We studied practitioner and practice characteristics which may explain differences in test ordering behaviour and in the extent to which general practitioners tend to change their behaviour according to the feedback. METHOD: In order to trace such variables, 75 general practitioners were interviewed. In our study request data from individual general practitioners were related to data from several questionnaires. RESULTS: We found no practice characteristics which were of influence on the number of test requests by the general practitioner. Explanatory practitioner characteristics for this were found to be years of experience and working hours per week in practice. CONCLUSIONS: More years of experience as a general practitioner and a shorter duration of consultations correlated with a better response to advice given in the feedback.

Adult↗
PubMed1995

Randomised controlled trial of routine individual feedback to improve rationality and reduce numbers of test requests.

Feedback can be described as a way to provide information on doctors' performance to enable changes in future behaviour. Feedback is used with the aim of changing test-ordering behaviour. It can lead to reductions in test usage and cost savings. It is not sufficiently clear, however, whether feedback leads to more appropriate test use. Since 1985, the Diagnostic Coordinating Center Maastricht has been giving feedback on diagnostic tests as a routine health care activity to all family doctors in its region. Both quantity and quality of requests are discussed. In a randomised, controlled trial over 2.5 years, discussion of tests not included previously was added to the existing routine feedback. One group of family doctors (n = 39) received feedback on test-group A (electrocardiography, endoscopy, cervical smears, and allergy tests), the other (n = 40) on test-group B (radiographic and ultrasonographic tests). Thus, each group of doctors acted as a control group for the other. Changes in volume and rationality of requests were analysed. The number of requests decreased during the trial (p = 0.036). Request numbers decreased particularly for test-group A (p = 0.04). The proportion of requests that were non-rational decreased more in the intervention than in the control groups (p = 0.009). Rationality improved predominantly for test-group B (p = 0.043). Thus, routine feedback can change the quantity and quality of requests.

Diagnostic Services↗
PubMed1995

The validity of urine examination for urinary tract infections in daily practice.

For urinary tract infections (UTI), diagnostic testing appears to be reliable and simple to perform. This particularly seems to hold true for test strips. In studies the validity of several urine tests proved to be high. These studies were, however, performed under optimal and standardized conditions. Their results therefore do not reflect daily practice. In this study the validity of urine tests for UTI is deterined under daily practice conditions, without the use of a protocol. The results show a validity considerably lower than under optimal conditions. Specificity in particular was lower, even for simple tests like the nitrite reaction. Under daily practice conditions, UTI can neither be confirmed nor excluded sufficiently on the outcome of a urinary sediment or test strip.

Adolescent↗
PubMed1995

Does a reduction in general practitioners' use of diagnostic tests lead to more hospital referrals?

BACKGROUND: Individual feedback on general practitioners' requests for tests can improve the quality of their test ordering behaviour. Little is known of the side effects on hospital referral behaviour when the use of tests is reduced through feedback. AIM: A study was undertaken to explore changes in general practitioners' hospital referral rates in a region where their use of diagnostic tests is reduced through feedback. METHOD: Trends in test requests and of first referrals to specialists were compared among 64 general practitioners in the Maastricht region of the Netherlands where routine feedback on test ordering behaviour is provided by the diagnostic coordinating centre. RESULTS: Reduction in diagnostic test use was not accompanied by a higher hospital referral rate, not even for specialties related to tests discussed in feedback. Good responders to feedback had decreased hospital referral rates in contrast to increased rates for poor responders (P < 0.01). CONCLUSION: Reducing the volume of general practitioners' diagnostic tests through feedback does not lead to more specialist referrals. Together with lower test use, fewer hospital referrals were seen.

Diagnostic Tests, Routine↗
PubMed1993

To test or not to test, that is the question.

This paper describes a system that is used in Maastricht, the Netherlands, to provide general practitioners with feedback about the adequateness of their test requesting behaviour. The system has proven to be effective. Since the screening of test requests and additional patient data is work-intensive a project was started in the framework of the AIM programme OPENLABS to design a computer-based feedback system. In this system the general practitioner sends test requests to the laboratory decision support system by means of electronic data interchange (EDI). The authors were involved in the development of the EDI messages, which are now accepted standards in the Netherlands. The requests are stored in a database that is part of the laboratory decision support system. The other part of the decision support system, an expert system, obtains the request data (including patient data) from the database, screens the requests for adequateness and provides feedback when necessary.

Clinical Laboratory Information Systems↗
PubMed1992

Effect of feedback on test ordering behaviour of general practitioners.

OBJECTIVE: To assess the effect of feedback on the test ordering behaviour of general practitioners. DESIGN: Comparison of requests at two diagnostic centres, and internal comparison between tests which were discussed in feedback and tests which were not. SETTING: A diagnostic centre in Maastricht giving feedback and another elsewhere in the Netherlands (laboratory A) not giving feedback. SUBJECTS: All 85 general practitioners in the region of Maastricht, and all general practitioners in the region of laboratory A. MAIN OUTCOME MEASURES: Numbers of tests requested by general practitioners. RESULTS: Requests at the Maastricht diagnostic centre decreased soon after the onset of feedback whereas there was a persistent increase in requests at laboratory A. Tests that were discussed showed the strongest decrease (maximum 40%), though tests that were not discussed decreased as well (maximum 27%). CONCLUSIONS: Feedback on diagnostic requests may exert a strong influence on request behaviour. Four years after the onset of feedback the effects were still noticeable.

Clinical Laboratory Techniques↗
PubMed1991

The reproducibility of urinalysis using multiple reagent test strips.

Ninety urine samples were examined twice by 3 "observers" (two persons, using only visual observation, and one person using a spectrophotometric analyser) using multiple reagent teststrips. To determine reproducibility, inter- and intra-observer agreement were calculated and expressed as Cohen's kappa and as weighted kappa. The results show negligible intra-observer differences between the visual and spectrophotometric observation. The lack of agreement between inter- and intra-observer urinalysis results, using multiple reagent test strips was disappointing, considering the simplicity of the test procedure. Further improvement of reproducibility, e.g. by enhancing the discoloration of the test pads, is necessary. Reproducibility is not improved by using a spectrophotometric analyser instead of visual reading of the test strips.

Esterases↗
PubMed1989

Different lengths of treatment with co-trimoxazole for acute uncomplicated urinary tract infections in women.

STUDY OBJECTIVE: To compare three days' and seven days' treatment with co-trimoxazole in women with acute dysuria, strangury, and urinary frequency or urgency. DESIGN: Randomised double blind placebo controlled trial. SETTING: General practices in the south east of The Netherlands. PATIENTS: 327 Non-pregnant female patients aged 12 to 65. INTERVENTION: 161 Women were allocated to three days' treatment (co-trimoxazole 960 mg twice a day), and 166 women were allocated to seven days' treatment (co-trimoxazole 960 mg twice a day). MAIN OUTCOME MEASURE: Resolution of symptoms at one, two, and six weeks. RESULTS: The rates for resolution of symptoms were not significantly different between the two groups. Cumulative rates of recurrence after three days' and seven days' treatment were 31/139 (22%) and 23/151 (15%) respectively six weeks after entry (p = 0.16). Adverse effects occurred in a quarter of women given three days' treatment compared with a third of women receiving seven days' treatment (p = 0.29). In only two patients did adverse effects necessitate stopping treatment. CONCLUSIONS: Three days of co-trimoxazole seems to be as effective as a seven days' course for treating acute urinary tract infection in non-pregnant women.

Adolescent↗
PubMed1989

A diagnostic centre for general practitioners: results of individual feedback on diagnostic actions.

A diagnostic centre, managing diagnostic tests for general practice, can improve the service provided by primary health care and the communication between general practitioners and specialists. In addition, it can evaluate the use and misuse of tests. This paper describes the work of a diagnostic centre in the Netherlands serving 80 general practitioners. Following the introduction of individual feedback to general practitioners on their use of diagnostic tests there was a decrease in the number of requests for tests.

Adult↗
PubMedDate not supplied

Routine individual feedback on requests for diagnostic tests: an economic evaluation.

The authors assessed the economic cor sequences of routine individual feedback on test requests provided to 85 family physicians in a region with 187,000 inhabitants. In a retrospective study as part of a quasi-experiment, cost trends in a region where feedback was provided over a seven-year period were compared with cost trends elsewhere in The Netherlands without feedback. Data on variable costs were obtained for 400 individual tests that accounted for 90% of all requests. Differences in request trends thus were transformed to savings in costs of diagnostic testing, taking account of the extra costs of providing the feedback. Expenditures for diagnostic testing declined after the start of the feedback, despite the costs of providing the feedback. The savings increased as the feedback continued. Compared with the trend elsewhere without feedback, over seven years a total net sum of 1.4 million U.S. dollars was saved. Routine individual feedback is therefore economically worthwhile.

Clinical Laboratory Techniques↗