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BACKGROUND: Prescribing of levothyroxine and rates of thyroid function testing may be sensitive to minor changes in the upper limit of the reference range for thyroid-stimulating hormone (TSH) that increase the proportion of abnormal results. We evaluated the population-level change in levothyroxine prescribing and TSH testing after a minor planned decrease in the upper limit of the reference range for TSH in a large urban centre with a single medical laboratory. METHODS: Using provincial administrative data, we compared predicted volumes of TSH tests with actual TSH test volumes before and after a planned change in the TSH reference range. We also determined the number of new levothyroxine prescriptions for previously untreated patients and the rate of changes to the prescribed dose for those on previously stable, long-term levothyroxine therapy before and after the change in the TSH reference range. RESULTS: Before the change in the TSH reference range, actual and predicted monthly volumes of TSH testing followed an identical course. After the change, actual test volumes exceeded predicted test volumes by 7.3% (95% confidence interval [CI] 5.3%–9.3%) or about 3000 to 5000 extra tests per month. The proportion of patients with newly “abnormal” TSH results almost tripled, from 3.3% (95% CI 3.2%–3.4%) to 9.1% (95% CI 9.0%–9.2%). The rate of new levothyroxine prescriptions increased from 3.24 (95% CI 3.15–3.33) per 1000 population in 2013 to 4.06 (95% CI 3.96–4.15) per 1000 population in 2014. Among patients with preexisting stable levothyroxine therapy, there was a significant increase in the number of dose escalations (p INTERPRETATION: Our findings suggest that clinicians may have responded to mildly elevated TSH results with new or increased levothyroxine prescriptions and more TSH testing. Knowledge translation efforts may be useful to accompany minor changes in reference ranges.

Objectives Helicobacter pylori stool antigen test (HpSAT) appropriateness was investigated by assessing its testing and positivity rates in Calgary, Canada. Methods The laboratory information system was accessed for all patients who received an HpSAT in 2018. Testing volume, test results, age, and sex of patients were collected. Sociodemographic risk factors and geospatial analysis were performed by matching laboratory data to the 2016 census data. Testing appropriateness was defined as a concordance between testing and positivity rates for each sociodemographic variable. Results In 2018, 25,518 H pylori stool antigen tests were performed in Calgary, with an overall positivity rate of 14.7%. Geospatial mapping demonstrated significant distribution variations of testing and positivity rates of HpSAT in the city. Certain sociodemographic groups studied (eg, recent immigrants) appeared to be appropriately tested (testing rate relative risk [RR] = 2.26, positivity rate RR = 4.32; P < .0001), while other groups (eg, male) may have been undertested (testing rate RR = 0.85, positivity rate RR = 1.14; P < .0001). Conclusions Determining concordance of testing and positivity rate of a laboratory test can be used for assessing testing appropriateness for other diseases in other jurisdictions. This study demonstrated some at-risk patients may be missed for H pylori testing.

Introduction The avoidance of repeat chemistry testing such as Complete Blood Count (CBC) and Electrolyte Panel (EP) on clinically stable patients was identified as important utilization goals by Choosing Wisely Canada. The purpose of this study was to assess the volume of overutilization of CBC and EP in an inpatient setting in Alberta, Canada, and provide an estimated cost assessment of unnecessary testing. Methods The total laboratory testing volumes of two common test panels were collected retrospectively for one-year from January to December 2018. Data was collected on test panels performed in an emergency room (ER) and inpatient setting from three separate Laboratory Information Systems covering the provincial population in Alberta, Canada. Total initial test panel instances, total repeated panels, repeated panels that were previously normal or abnormal, and estimated costs were examined. Cost assessment was completed based on Reference Median Cost (RMC) analysis for each of these two common test panels. Results During the study period, 2,020,467 (CBC) and 1,455,983 (EP) initial test panel instances were recorded, of which 67.7% and 73.5% were repeated for the CBC and EP, respectively. There was a higher proportion of EP repeated inappropriately (previously normal; 35.6%) compared to CBCs (5.4%). The cost to the province for inappropriately repeating CBC and EP were estimated to be RMC $0.52 million and RMC $1.90 million CAD, respectively. Conclusion Results from this study can assist policy makers in implementing utilization management initiatives and update clinical practice guidelines to reduce costs to healthcare without compromising patient care.

Background There is widespread variation in testing practice among practitioners, however there has been no objective way to pinpoint target tests for utilization management. We propose to take advantage of inter-physician variance in clinical practice as a quantitative measure to generate lists of potentially misutilized tests. Methods Testing frequencies from a database of clinical testing volumes for outpatients in Calgary, Canada, were obtained for the study period of 2016. For each chemistry, microbiology or hematology test, an arithmetic coefficient of variation (CV) was calculated from family physicians' ordering frequencies. Results The mean CV for all 358 tests considered was 219% (95% CI 206–231%) with a range of 52–729%. The highest variance was observed for human T-lymphotropic virus antibody testing and several tests for heavy metal levels (mercury, copper, zinc and chromium). Among the 100 most commonly run tests, high variance was found for several endocrinology tests including cortisol. Conclusions The utility of ranking clinical tests by ordering variance presents a practical approach to evaluate relative variation in physician practice strategy and to identify potential areas of misutilization.

While there is concern about excessive laboratory test ordering in the ED, it is difficult to quantify the problem. One solution involves the Mean Abnormal Result Rate (MARR), which is the proportion of tests ordered that return abnormal results. The primary objective of this study was to calculate MARR scores, and factors associated with MARR scores, for tests ordered between April 2014 and March 2019 at adult EDs in Calgary.Administrative data were obtained for 40 laboratory tests that met selection criteria. One possible MARR correlate, physician experience, was quantified for 209 ED physicians as number of years since licensure. Analyses were descriptive where appropriate for whole-population data.The condensed dataset comprised 3,395,312 test results on 415,653 unique patients. The aggregate 5-year MARR score was 40.1%. The highest per-test score was for BNP (80.5%), while the lowest was for glucose (7.9%). MARR scores were higher for nurse-initiated orders than for physician-initiated orders (44.7% vs. 38.1%). The MARR score correlated inversely with number of tests per order (r = - 0.90; 95% confidence interval [CI] - 0.65 to - 0.94; p 0.001) and directly with physician experience (r = 0.28, 95% CI 0.20 to 0.27; p 0.001).This is the first study to measure MARR scores in an ED setting. While lower scores (close to 5%) are less optimal in principle, ideal scores will depend on the clinical context in which tests are used. However, once departmental benchmarks are established, MARR score-monitoring allows efficient tracking of ordering practices across millions of tests.RéSUMé: OBJECTIFS: Bien que l'on s'inquiète d'une commande excessive de tests de laboratoire dans le service d'urgence, il est difficile de quantifier le problème. Une solution implique le taux de résultat anormal moyen (MARR), qui est la proportion de tests commandés qui renvoient des résultats anormaux. L'objectif principal de cette étude était de calculer les scores MARR, et les facteurs associés aux scores MARR, pour les tests commandés entre avril 2014 et mars 2019 dans les services d'urgence pour adultes à Calgary. LES MéTHODES: Des données administratives ont été obtenues pour 40 tests de laboratoire répondant aux critères de sélection. Une corrélation possible du MARR, soit l’expérience des médecins, a été quantifié pour 209 médecins urgentistes en nombre d'années depuis l'autorisation d'exercer. Les analyses étaient descriptives, le cas échéant, pour les données sur l’ensemble de la population. RéSULTATS: L'ensemble de données condensé comprenait 3,395,312 résultats de tests sur 415 653 patients uniques. Le score MARR global à 5 ans était de 40,1%. Le score le plus élevé par test était pour le peptide cérébral natriurétique BNP (80,5%), tandis que le plus bas était pour le glucose (7,9%). Les scores de MARR sont plus élevés pour les ordonnances initiées par les infirmières que pour les ordonnances initiées par les médecins (44,7% contre 38,1%). Le score MARR s’est corrélé inversement avec le nombre de tests par ordre (r = − 0,90; intervalle de confiance de 95 % [IC] − 0.65 to − 0,94; p 0.001) et directement avec l’expérience du médecin (r = 0.28, IC à 95 % 0.20–0.27; p 0.001). CONCLUSIONS: Il s’agit de la première étude à mesurer les scores du MARR dans un contexte de service d’urgence. Bien que des scores inférieurs (près de 5%) sont moins optimaux en principe, les scores idéaux dépendront du contexte clinique dans lequel les tests sont utilisés. Cependant, une fois les points de repère ministériels établis, la surveillance des scores du MARR permet de suivre efficacement les pratiques de commande sur des millions de tests.

Objectives The mean abnormal result rate (MARR) has recently been advanced as a metric of laboratory test appropriateness. We used the MARR metric to examine patterns of change in family physician test requisitions over time. Methods We accessed the Laboratory Information System of Calgary Laboratory Services for family physician-ordered testing on outpatients to gather aggregate test and abnormal result counts from 2010 to 2015. Results Over the 6 years, there was an annual average of 3,401,553 tests for 411,295 distinct patients on their first test requisition for the year. The MARR increased from 8.1% to 9.0% through this period. Conclusions The MARR for Calgary and surrounding area gives tentative evidence of a gradual increase in physician test selectivity in recent years. Further data from other catchment areas are needed before making assertions about broader trends in physician awareness of laboratory resource use.

Objectives The increasing cost of clinical laboratory testing is a challenge in our health care system. This study aims to calculate the annual clinical laboratory test costs attributed to patients in a major Canadian city and to correlate them to their sociodemographic variables. Methods Retrospective cohort study involving patients who received clinical chemistry, hematology, and microbiology tests in 2011 in Calgary, Canada (n = 610,409). Test volumes were obtained from a laboratory informatics database. Total expenditures per patient were calculated using estimated test costs and then combined with the 2011 Canadian Census Household Survey results to infer sociodemographic correlates. Results While more women received laboratory testing (58.4%), men had slightly higher testing costs per capita. Except for Chinese, visible minority and Aboriginal populations had higher testing costs. There was an inverse correlation between testing cost and household income, and accordingly, higher costs were found in those without postsecondary education and the unemployed. Furthermore, hotspot mapping revealed the geographical distribution of patient test costs within the city. Conclusions There is variation in testing costs for patients among different sociodemographic variables.

Background The first Canadian outbreak of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) was identified in 2004 in Calgary, Alberta. Using a novel model of MRSA population-based surveillance, sociodemographic risk associations, yearly geospatial dissemination and prevalence of CA-MRSA infections over an 11 year period was identified in an urban healthcare jurisdiction of Calgary. Methods Positive MRSA case records, patient demographics and laboratory data were obtained from a centralized Laboratory Information System of Calgary Laboratory Services in Calgary, Alberta, Canada between 2004 and 2014. Public census data was obtained from Statistics Canada, which was used to match with laboratory data and mapped using Geographic Information Systems. Results During the study period, 52.5% of positive MRSA infections in Calgary were CA-MRSA cases. The majority were CMRSA10 (USA300) clones (94.1%; n = 4255), while the remaining case (n = 266) were CMRSA7 (USA400) clones. Period prevalence of CMRSA10 increased from 3.6 cases/100000 population in 2004, to 41.3 cases/100000 population in 2014. Geospatial analysis demonstrated wide dissemination of CMRSA10 annually in the city. Those who are English speaking (RR = 0.05, p

We describe the implementation of an Alberta-wide intervention aimed at educating clinicians about redundant vitamin BWe performed a cross-sectional observational study that included all vitamin BOver the sum of the first 12 months of the intervention, 18,000 more vitamin BAn educational intervention aimed at limiting inappropriate vitamin B

Objectives : There is a need to develop and validate new metrics to access the appropriateness of laboratory test requests. Methods: The mean abnormal result rate (MARR) is a proposed measure of ordering selectivity, the premise being that higher mean abnormal rates represent more selective test ordering. As a validation of this metric, we compared the abnormal rate of lab tests with the number of tests ordered on the same requisition. We hypothesized that requisitions with larger numbers of requested tests represent less selective test ordering and therefore would have a lower overall abnormal rate. Results: We examined 3,864,083 tests ordered on 451,895 requisitions and found that the MARR decreased from about 25% if one test was ordered to about 7% if nine or more tests were ordered, consistent with less selectivity when more tests were ordered. We then examined the MARR for community-based testing for 1,340 family physicians and found both a wide variation in MARR as well as an inverse relationship between the total tests ordered per year per physician and the physician-specific MARR. Conclusions: The proposed metric represents a new utilization metric for benchmarking relative selectivity of test orders among physicians.

Background The Canadian Diabetes Association recommends testing most individuals with diabetes mellitus using HbA1c once every 3 months. In Alberta, Canada, a provincial intervention to reduce inappropriate HbA1c test orders was implemented to align with this guideline, where only one HbA1c test request every 90 days for most individuals can be processed. Here, we evaluated the provincial intervention to reduce redundant HbA1c testing in Alberta. Methods Total counts of all HbA1c tests ordered within Edmonton and Calgary, Alberta, were collected from the respective Laboratory Information Systems each month between January 2013 and December 2016. Winters' Additive time series model was built to predict the HbA1c test volume after intervention (November 1, 2015 onwards) and compared with the observed test volume to estimate the effect of the intervention. The estimated change in test volume was then multiplied by the estimated cost to determine the economic impact. Results During the first 14 months of the intervention for Alberta, there was a 3.3% reduction in the number of observed HbA1c tests compared to the predicted volume. With an estimated marginal reagent cost of $3.50 per unit, this resulted in a cost savings of $145,422 in the first 14 months of the provincial intervention. Conclusion A modest reduction in HbA1c test orders was observed in the urban areas of Alberta since the implementation of this provincial initiative.

Objective The incidence of the combined myeloproliferative neoplasms (MPNs) was determined for a major Canadian city. Retrospective cases of MPN diagnoses (essential thrombocythemia, polycythemia vera, and primary myelofibrosis) between 2011 to 2015 were retrieved from the Southern Alberta Cancer Cytogenetics Laboratory’s database at Alberta Public Laboratories. Results An incidence rate of 2.05 cases per 100,000 person-years (95% CI 1.73–2.41) was determined, giving an age-standardized Canadian incidence of 2.71 cases per 100,000 person years (95% CI 2.63–2.78). MPN diagnoses occurred at a wide age range of 8–93 (median 66) and an age-dependent increase in incidence. Incidence rates for the MPNs are first reported here for a Canadian population.

Objective The epidemiology of chronic myeloid leukemia is shifting due to the aging global population and the recent discovery and availability of targeted treatment options. This study provides recent data regarding the incidence of CML in Calgary, a major Canadian city. Data from patients diagnosed with CML by bone marrow sample analysis from 2011 to 2015 were collected from the database of the sole centralized cytogenetics facility in service of Calgary and its surrounding area. Results With an average of 10.2 newly diagnosed cases per year in Calgary from 2011 to 2015, the incidence rate was calculated to be 0.75 cases per 100,000 person-years (95% CI 0.57–0.99). With age standardization, the incidence was 0.87 cases per 100,000 person-years (95% CI 0.82–0.91) for the Canadian population, which was low compared to other developed Western nations. The highest incidence rates were observed in the older patient categories, however there was a broad age distribution for incident cases and the median age at diagnosis was 48. There was a general male bias for CML most pronounced at the younger ages. Our description of CML incidence will help to inform healthcare planners amidst the dramatically altered treatment of this hematological neoplasm.

Background Chronic kidney disease (CKD) is often asymptomatic in its early stages but is indicated and is diagnosed with an estimated glomerular filtration rate (eGFR)

Objectives Mitigation of unnecessary and redundant laboratory testing is an important quality assurance priority for laboratories and represents an opportunity for cost savings in the health care system. Family physicians represent the largest utilizers of laboratory testing by a large margin. Engagement of family physicians is therefore key to any laboratory utilization management initiatives. Despite this, family physicians have been largely excluded from the planning and implementation of such initiatives. Our purposes were to (1) assess the importance of lab management issues to family physicians, and (2) attempt to define the types of initiatives most acceptable to family physicians. Design and methods We invited all Alberta family practice residents and practicing physicians to participate in a self-administered online electronic survey. Survey questions addressed the perceived importance of lab misutilization, prevalence of various types of misutilization, acceptability of specific approaches to quality control, and responsibility of various parties to address this issue. Results Of 162 respondents, 95% considered lab misutilization to be either important or very important. Many physicians placed the responsibility for addressing lab misutilization issues on multiple parties, including patients, but most commonly the ordering physician (97%). Acceptability for common strategies for quality improvement in lab misutilization showed a wide range (35%–98%). Conclusions These responses could serve as a framework for laboratories to begin discussions on this important topic with primary care groups.

Objective Acute lymphocytic leukemia (ALL) is a rare malignant neoplasm that develops from abnormal lymphoid stem cells. ALL incidence is highest among children and declines towards adolescence. There is limited data on the epidemiology of ALL, especially in Canada. This retrospective cohort study used patient data from the Calgary Laboratory Services Cancer Cytogenetics Laboratory to report the incidence rate of ALL in Calgary, Alberta, Canada. New cases of ALL were identified for the 5-year period of January 1, 2011 until December 31, 2015. Reported incidence rates were categorized by sex and age groups, and age-standardized to the Canadian population. Results There were an average of 11.4 new cases of ALL diagnosed per year between 2011 and 2015. The total incidence rate per 100,000 person-years was 0.84. Incidence rates peaked in children aged 0–4 with 7.55 and 3.32 cases per 100,000 person-years for males and females, respectively. The median age of diagnosis was 8 years. Incidence rates were generally lowest for adults aged 20 and over. The ratio of males to females diagnosed with ALL was 1.59. Overall, the recent incidence of ALL in Calgary is comparatively low with a preference for males and children below 5 years of age.

Aim: Chlamydia trachomatis is the most prevalent bacterial sexually transmitted infection in developed nations and is an important public health concern. We aimed to assess the factors associated with testing and positivity of C. trachomatis in a large population. Methods: A retrospective study of a large Canadian health region was undertaken using 2011 census and laboratory data. Demographic and socioeconomic data from the national household survey were linked to microbiologic data for C. trachomatis. Multivariable generalized estimating equation models were constructed to examine relative risk for C. trachomatis testing and positivity. Results: For testing and positivity, female sex and younger age groups were associated with increased risk. University education and South Asian ethnicity were associated with lower risk of positivity. Conclusion: Incorporating socio-demographic factors will be critical to the success of future sexually transmitted infection public health programs.

Objectives Approaches to determining optimal locations for patient service centers (phlebotomy clinics) have not been addressed in the published literature. Using the city of Calgary, Alberta, Canada, as a test case, our objective is to present a novel method for determining underserviced geographic areas within a city to guide the choice of potential new patient service center locations. Methods Data on travel distances for 198,883 phlebotomy visits as well as population data from the 2011 Canada Census were used for this study. Using geospatial mapping techniques, we produced maps of the city showing actual relative travel distances for patients as well as the geographic distribution of population density of patients undergoing phlebotomies. Results There was a striking pattern of increased travel distances in certain parts of the city. These also corresponded to geographic areas with greater density of patients seeking phlebotomies. Conclusions This analysis provided clear, objective evidence of communities that are currently relatively underserved by patient service centers. This approach could be used by other laboratories to plan the location of new patient service centers.

Objectives: Very little is known about the relative contributions of physician specialty groups and individual physicians to overall clinical laboratory expenditures. The objectives of this study were to determine the costs of clinical laboratory test expenditures attributable to 30 medical specialties and the associated per capita physician expenditures for an entire major Canadian city. Only chemistry, hematology, and microbiology tests were included in this study. Methods: Retrospective cohort study involving all physicians in Calgary, Canada, and surrounding areas (n = 3,499) and secondary data on laboratory test orders. Results: Data were obtained on approximately 20 million test requests. The mean clinical laboratory test expenditure, in Canadian dollars, per physician was $27,945 for all physicians combined. Total expenditures by primary care physicians (family physicians and general practitioners) accounted for 58% of total expenditures. Conclusions: There was wide variation in clinical laboratory test expenditures among specialties and on a per capita basis within medical specialties.