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

Primary care use of laboratory tests in Northern Ireland's Western Health and Social Care Trust: a cross-sectional study

OBJECTIVES

To describe the laboratory test ordering patterns by general practitioners (GPs) in Northern Ireland Western Health and Social Care Trust (WHSCT) and explore demographic and socioeconomic associations with test requesting.

DESIGN

Cross-sectional study.

SETTING

WHSCT, Northern Ireland. : Particip ANTS: 55 WHSCT primary care medical practices that remained open throughout the study period 1 April 2011-31 March 2016.

OUTCOMES

To identify the temporal patterns of laboratory test ordering behaviour for eight commonly requested clinical biochemistry tests/test groups in WHSCT. To analyse the extent of variations in laboratory test requests by GPs and to explore whether these variations can be accounted for by clinical outcomes or geographical, demographic and socioeconomic characteristics.

RESULTS

The median number of adjusted test request rates over 5 consecutive years of the study period decreased by 45.7% for urine albumin/creatinine ratio (p<0.000001) and 19.4% for lipid profiles (p<0.000001) while a 60.6%, 36.6% and 29.5% increase was observed for HbA_1c (p<0.000001), immunoglobulins (p=0.000007) and prostate-specific antigen (PSA) (p=0.0003), respectively. The between-practice variation in test ordering rates increased by 272% for immunoglobulins (p=0.008) and 500% for HbA_1c (p=0.0001). No statistically significant relationship between ordering activity and either demographic (age and gender) and socioeconomic factors (deprivation) or Quality and Outcome Framework scores was observed. We found the rural-urban differences in between-practice variability in ordering rates for lipid profiles, thyroid profiles, PSA and immunoglobulins to be statistically significant at the Bonferroni-adjusted significance level p<0.01.

CONCLUSIONS

We explored potential factors of the interpractice variability in the use of laboratory tests and found that differences in requesting activity appear unrelated to either demographic and socioeconomic characteristics of GP practices or clinical outcome indicators.

Physician and practice characteristics associated with immunoglobulin test ordering

BACKGROUND

Primary care test requests for serum immunoglobulins are rising rapidly, with concerns that many requests may be unnecessary. Evidence suggests some characteristics of general practitioners (GPs) and practices are associated with higher test ordering.

OBJECTIVE

To identify the physician and practice characteristics associated with immunoglobulin test ordering.

METHODS

Retrospective, cross-sectional study using routine laboratory data on primary care serum immunoglobulin requests. Data were linked with GP patient list size data. The primary outcome measure was the count of test requests per GP. Predictor variables were physician gender, years experience, practice region and type (number of GPs), GP patient list size and composition. Mixed-effects multilevel regression models were used to calculate incidence rate ratios (IRRs) with 95% confidence intervals (CIs) for the associations between physician and practice characteristics and GP requesting. Sensitivity analysis was performed by limiting the model to the more than 70 years age category.

RESULTS

In total, 5990 immunoglobulin tests were ordered by 481 GPs in the South of Ireland during 2013. The number of tests ordered by individual GPs varied from one to 377. In the final fully adjusted Poisson regression analysis, female gender (IRR: 1.81; 95% CI: 1.45-2.26) and less experience (IRR: 2.27; 95% CI: 1.47-3.51) were associated with higher requesting (P < 0.001). None of the practice factors were associated with test ordering. Sensitivity analysis on the 70 years or more age category found similar results.

CONCLUSION

Further research is required to explore the potential reasons for higher requesting among GPs with fewer years of experience and also among female GPs.

Do Pediatric Patients Who Receive Care Across Multiple Health Systems Have Higher Levels of Repeat Testing?

Repetition by clinicians of the same tests for a given patient is common. However, not all repeat tests are necessary for optimal care and can result in unnecessary hardship. Limited evidence suggests that an electronic health record may reduce redundant laboratory testing and imaging by making previous results accessible to physicians. The purpose of this study is to establish a baseline by characterizing repeat testing in a pediatric population and to identify significant risk factors associated with repeated tests, including the impact of using multiple health systems. A population-based retrospective cross-sectional design was used to examine initial and repeat test instances, defined as a second test following an initial test of the same type for the same patient. The study population consisted of 8760 children with 1-25 test claims over a 1-year period. The study setting included all health care service organizations in Minnesota that generated these claims. In all, 17.2% of tests met the definition of repeat test instances, with several risk factors associated with per patient repeat test levels. The incidence of repeat test instances per patient was significantly higher when patients received care from more than 1 health system (adjusted incidence rate ratio 1.4; 95% confidence interval: 1.3-1.5). Repeat test levels are significant in pediatric populations and potentially actionable. Interoperable health information technology may reduce the incidence of repeat test instances in pediatric populations by making prior test results readily accessible. (Population Health Management 2016;19:102-108).

Improvement in deployment of MRI of the sacroiliac joints in patients suspected for spondyloarthritis using a targeted intervention: a case study

OBJECTIVE

To assess characteristics of deployment of MRI of the SI joints (MR-SI) in patients with suspected axial spondyloarthritis (SpA) before and after a targeted intervention.

METHODS

In a retrospective chart review study, all MR-SI performed in the period 1 April 2004 to 31 December 2010 were collected. Inclusion criteria were complete patient data and MR-SI ordered by a rheumatologist for suspicion of axial SpA. MR-SI reports were graded as normal, suspected sacroiliitis or sacroiliitis. In April 2007 an intervention was made to improve deployment. Rheumatologists were provided with data on ordering behaviour, patient characteristics and MRI outcomes. An introduction on the effect of pretest chance on positive and negative predictive value was given; the burden for patients and costs was illustrated. An alternative behavioural strategy was offered in the form of a simple diagnostic algorithm. Percentages of MRIs and positive MRI for sacroiliitis were compared before and after intervention.

RESULTS

From April 2004 to April 2007, 198 MR-SIs were performed, of which 166 (83.9%) were normal, 5 (2.5%) were suspicious and 27 (13.6%) were positive. After the intervention, patients displayed significantly more SpA features. More optimal patient selection resulted in 79 MR-SI requests, a decrease of 60.1%. Fifty-seven (72.2%) reports were normal, 0 were suspicious and 22 (27.8%) were positive.

CONCLUSION

A simple, one-time, five-step feedback intervention resulted in a 60% reduction in MR-SI requests with a doubling of the percentage of MR-SI positive for sacroiliitis. This approach may benefit future research in areas with diagnostic uncertainty and suboptimal testing.

Reasons for ordering laboratory tests and relationship with frequency of abnormal results

OBJECTIVE

Laboratory tests are ordered on a daily basis, even though disease probability is often very low. Abnormal results, especially mildly abnormal results, can be difficult to interpret in these circumstances. Further insights into the occurrence of abnormalities can help improve rational test ordering and test interpretation. The objective was therefore to examine the frequency of mildly and markedly abnormal results and their relationship with physicians' reasons for ordering tests.

DESIGN

Prospective study. Participants. A total of 87 primary care physicians in the Netherlands collected data on 1775 patients.

MAIN OUTCOME MEASURES

The physicians recorded the reason for ordering the tests, the most probable diagnosis and the pretest probability. The laboratories' reference values and specified "action limits" were used to assess the number of abnormal results and markedly abnormal results, respectively.

RESULTS

Laboratory results were received for 1621 patients and 15,603 tests were reported (mean 9.6). The proportion of abnormal test results increased with increasing pretest probability (from 13.9% to 34.7%) and was 13.4% for tests ordered to reassure the patient and 13.3% for psychosocial diagnoses. The proportion of patients with at least one abnormal test result was high: 53.1% for tests ordered to reassure and 57.7% in patients with low pretest probability. Corresponding values for a marked abnormality were 11.1% and 12.4%, respectively.

CONCLUSION

Abnormal laboratory test results were frequent, even when pretest probability was low. Physicians should therefore carefully consider when tests are necessary. Future research could explore physicians' interpretation of test results and its impact on diagnosis and management.

Long-term effects of an education programme on the optimal use of clinical chemistry testing in primary health care

OBJECTIVE

The aim of this study was to investigate whether continuing education on the optimal use of clinical chemistry testing in primary health care has had any long-term effects on the test-ordering behaviour of the participating physicians.

METHODS

The effects were monitored using 12 laboratory test ratios. Twenty-three general practitioners at 16 primary health-care centres in the county of Uppsala, Sweden, participated. A sign test was used to evaluate how individual physicians' test-ordering patterns have changed during the 8 years since implementation of the educational programme. Maintained or improved ratios were interpreted as a sustained effect on the primary health-care physician's test-ordering habits.

RESULTS

Eleven out of 12 of the investigated ratios were the same or improved since the time of the short-term follow-up 6 months after the education.

CONCLUSION

A short continuation course on optimal use of clinical chemistry assays can achieve permanent changes in the test-ordering patterns of primary health-care physicians. These findings highlight education as one possible means towards achieving cost-efficiency and quality in test-ordering.

A review identifies and classifies reasons for ordering diagnostic tests

OBJECTIVE

To consider the reasons and context for test ordering by doctors when faced with an undiagnosed complaint in primary or secondary care.

STUDY DESIGN AND SETTING

We reviewed any study of any design that discussed factors that may affect a doctor's decision to order a test. Articles were located through searches of electronic databases, authors' files on diagnostic methodology, and reference lists of relevant studies. We extracted data on: study design, type of analysis, setting, topic area, and any factors reported to influence test ordering.

RESULTS

We included 37 studies. We carried out a thematic analysis to synthesize data. Five key groupings arose from this process: diagnostic factors, therapeutic and prognostic factors, patient-related factors, doctor-related factors, and policy and organization-related factors. To illustrate how the various factors identified may influence test ordering we considered the symptom low back pain and the diagnosis multiple sclerosis as examples.

CONCLUSIONS

A wide variety of factors influence a doctor's decision to order a test. These are integral to understanding diagnosis in clinical practice. Traditional diagnostic accuracy studies should be supplemented with research into the broader context in which doctors perform their work.

Unnecessary repeat requesting of tests: an audit in a government hospital immunology laboratory

Unnecessary repeat requesting of tests can make up a large proportion of a laboratory's workload. This audit set out to establish the size of this problem and to identify the circumstances under which these repeat requests were made in a government tertiary hospital immunology laboratory. The numbers of tests for immunoglobulin measurement, common autoantibodies, and tumour markers that were repeated over a 12 month period were analysed by interrogating the Delphic laboratory computer system using a management information system for raw data enquiry protocol. Repeat requests within 12 weeks of a previous request made up 16.78% of the total workload. The total cost of the tests was estimated at 132 151 US dollars. The waste of technician time and reagents as a result of unnecessary repeat testing is excessive. Many of these tests might be eliminated with the use of interventions such as computerised reminders.

Variation in requests for imaging investigations by general practitioners: a multilevel analysis

OBJECTIVES

To describe the variation in the numbers of imaging investigations requested by general practitioners (GPs) and to find likely explanations for this variation.

METHODS

Cross-sectional survey of the use of eight imaging investigations by 229 GPs collaborating in 40 local GP groups from five regions in the Netherlands during 1997. A multivariable, multilevel regression analysis was used to link these data with survey data on professional characteristics such as knowledge about and attitude towards test ordering, and with data on contextual factors such as practice type or experience with feedback on test-ordering data.

RESULTS

Data for 221 GPs (97%) were available. After adjustment for practice size and working time, the median number of imaging investigations ordered per GP was 148 (interquartile range 71 to 300), with large differences (up to twofold) between the regions (P<0.001). Overall, chest X-rays were the largest single category (median = 48 interquartile range 17 to 100). GPs working in a group practice requested, on average, 34% fewer investigations than their colleagues working in single-person practices (95% confidence interval 17 to 48%).

CONCLUSIONS

Only practice type was found to be associated with the number of imaging investigations requested, adjusted for practice size and working time factor. No further explanations were found for the inter-regional differences. Future studies on the ordering of imaging investigations by GPs should attempt to delineate contextual from regional factors.

Compliance of General Practitioners with a Guideline-based Decision Support System for Ordering Blood Tests

Background: Guidelines are viewed as a mechanism for disseminating a rapidly increasing body of knowledge. We determined the compliance of Dutch general practitioners with the recommendations for blood test ordering as defined in the guidelines of the Dutch College of General Practitioners.

Methods: We performed an audit of guideline compliance over a 12-month period (March 1996 through February 1997). In an observational study, a guideline-based decision support system for blood test ordering, BloodLink, was integrated with the electronic patient records of 31 general practitioners practicing in 23 practices (16 solo). BloodLink followed the guidelines of the Dutch College of General Practitioners. We determined compliance by comparing the recommendations for test ordering with the test(s) actually ordered. Compliance was expressed as the percentage of order forms that followed the recommendations for test ordering.

Results: Of 12 668 orders generated, 9091 (71%) used the decision-support software rather than the paper order forms. Twelve indications accounted for &gt;80% of the 7346 order forms that selected a testing indication in BloodLink. The most frequently used indication for test ordering was “vague complaints” (2209 order forms; 30.1%). Of the 7346 order forms, 39% were compliant. The most frequent type of noncompliance was the addition of tests. Six of the 12 tests most frequently added to the order forms were supported by revisions of guidelines that occurred within 3 years after the intervention period.

Conclusions: In general practice, noncompliance with guidelines is predominantly caused by adding tests. We conclude that noncompliance with a guideline seems to be partly caused by practitioners applying new medical insight before it is incorporated in a revision of that guideline.