Breast Density and Risk of Interval Cancers: The Effect of Annual Versus Biennial Screening Mammography Policies in Canada.

Regular screening mammography reduces breast cancer mortality. However, in women with dense breasts, the performance of screening mammography is reduced, which is reflected in higher interval cancer rates (ICR). In Canada, population-based screening mammography programs generally screen women biennially; however, some provinces and territories offer annual mammography for women with dense breast tissue routinely and/or on recommendation of the radiologist. This study compared the ICRs in those breast screening programs with a policy of annual vs. those with biennial screening for women with dense breasts. Among 148,575 women with dense breasts screened between 2008 to 2010, there were 288 invasive interval breast cancers; screening programs with policies offering annual screening for women with dense breasts had fewer interval cancers 63/70,814 (ICR 0.89/1000, 95% CI: 0.67-1.11) compared with those with policies of usual biennial screening 225/77,761 (ICR 1.45 /1000 (annualized), 95% CI: 1.19-1.72) i.e. 63% higher (p = 0.0016). In screening programs where radiologists' screening recommendations were able to be analyzed, a total of 76,103 women were screened, with 87 interval cancers; the ICR was lower for recommended annual (65/69,650, ICR 0.93/1000, 95% CI: 0.71, 1.16) versus recommended biennial screening (22/6,453, ICR 1.70/1000 (annualized), 95%CI: 0.70, 2.71)(p = 0.0605). Screening program policies of annual as compared with biennial screening in women with dense breasts had the greatest impact on reducing interval cancer rates. We review our results in the context of current dense breast notification in Canada.

Using personal health insurance numbers to link the Canadian Cancer Registry and the Discharge Abstract Database.

BACKGROUND: Linking cancer registry and administrative data can reveal health care use patterns among cancer patients. The Canadian Cancer Registry (CCR) contains personal health insurance numbers (HINs) that facilitate linkage to hospitalization information in the Discharge Abstract Database (DAD). DATA AND METHODS: Valid HINs, captured in the CCR or obtained through probabilistic linkages to provincial health insurance registries, were used to deterministically link prostate, female breast, colorectal and lung cancers diagnosed from 2005 through 2008 with the DAD for fiscal years 2004/2005 to 2010/2011. RESULTS: At least 98% of tumours diagnosed from 2005 through 2008 had valid HINs in the CCR or obtained through probabilistic linkages. For provinces submitting day surgeries to the DAD, linkage rates to at least one DAD record were higher for female breast (95.6% to 98.1%), colorectal (96.9% to 98.7%) and lung cancers (92.8% to 96.3%) than for prostate cancers (77.2% to 91.6%). Among linked records, agreement was high for sex (99% or more) and complete date of birth (97% or more); the likelihood of a consistent diagnosis in the CCR and on at least one linked DAD record was higher for female breast (86.8% to 97.2%), colorectal (94.6% to 97.7%) and lung cancers (90.3% to 95.5%) than for prostate cancers (77.4% to 87.8%). INTERPRETATION: Deterministically linking the CCR and DAD using personal HINs is a feasible and valid approach to obtaining hospitalization information about cancer patients.

Corrigendum: Second malignant neoplasms within 5 years from first primary diagnosis in pediatric oncology patients in Canada: a population-based retrospective cohort study.

[This corrects the article DOI: 10.3389/fonc.2024.1376652.].

Second malignant neoplasms within 5 years from first primary diagnosis in pediatric oncology patients in Canada: a population-based retrospective cohort study.

Introduction: From the advancement of treatment of pediatric cancer diagnosis, the five-year survival rate has increased significantly. However, the adverse consequence of improved survival rate is the second malignant neoplasm. Although previous studies provided information on the incidence and risk of SMN in long term survivors of childhood cancer, there is still scarce information known for short term (< 5 years) prognosis. This study aims to assess the incidence, characteristics, management, and outcome of children who develop SMN malignancies within 5 years of diagnosis of their initial cancer. Method: This is a retrospective cohort study of early Second Malignant Neoplasms (SMN) in pediatric oncology patients. The Cancer in Young People - Canada (CYP-C) national pediatric cancer registry was used and reviewed pediatric patients diagnosed with their first cancer from 2000-2015. Results: A total of 20,272 pediatric patients with a diagnosis of a first malignancy were analyzed. Of them, 0.7% were diagnosed with a SMN within the first 5 years following their first cancer diagnosis. Development of a SMN impacted survival, shown by an inferior survival rate in the SMN cohort (79.1%) after three years compared to that of the non-SMN cohort (89.7%). Several possible risk factors have been identified in the study including the use of epipodophyllotoxins, exposure to radiation, and hematopoietic stem cell 169 transplant. Discussion: This is the first national study assessing the incidence, 170 characteristics, risk factors and outcome of early SMN in Canadian children 171 from age 0-15 from 2000-2015.

Post-COVID-19 condition symptoms among emergency department patients tested for SARS-CoV-2 infection.

Symptoms of the Post-COVID-19 Condition are often non-specific making it a challenge to distinguish them from symptoms due to other medical conditions. In this study, we compare the proportion of emergency department patients who developed symptoms consistent with the World Health Organization's Post-COVID-19 Condition clinical case definition between those who tested positive for Severe Acute Respiratory Syndrome Coronavirus-2 infection and time-matched patients who tested negative. Our results show that over one-third of emergency department patients with a proven acute infection meet Post-COVID-19 Condition criteria 3 months post-index visit. However, one in five test-negative patients who claim never having been infected also report symptoms consistent with Post-COVID-19 Condition highlighting the lack of specificity of the clinical case definition. Testing for SARS-CoV-2 during the acute phase of a suspected infection should continue until specific biomarkers of Post-COVID-19 Condition become available for diagnosis and treatment.

An examination of the NAACCR method of assessing completeness of case ascertainment using the Canadian Cancer Registry.

BACKGROUND: Despite use of the North American Association of Central Cancer Registries' indicator for assessing completeness of case ascertainment in population-based cancer registries, little has been published about its methodology, usefulness and accuracy in Canada. DATA AND METHODS: Canadian cancer incidence, cancer mortality, and population census data were used to quantify case completeness in 2007. Two indicators (I1 and I2) that expressed the observed age-standardized incidence rate relative to the expected rate were calculated. The assumption of stable age-standardized sex- and cancer-site-specific incidence-to-mortality rate ratios across regions was assessed. Associations between I1, I2 and simpler indicators of completeness were examined. RESULTS: The assumption of stable age-standardized sex- and cancer-site-specific incidence-to-mortality rate ratios across regions was not consistently supported­substantial regional differences emerged. I1 was strongly correlated with I2 (r=0.93, n=315, p<0.0001), and both were most strongly and consistently associated with the age-standardized incidence-to-mortality rate ratio. The frequency of undercoverage did not increase consistently with expected case-finding difficulty. INTERPRETATION: The age-standardized incidence-to-mortality rate ratio may provide a less complicated method of identifying undercoverage.

Associations between chronic conditions and death in hospital among adults (aged 20+ years) during first acute care hospitalizations with a confirmed or suspected COVID-19 diagnosis in Canada.

PURPOSE: We aimed to quantify life course-specific associations between death in hospital and 30 chronic conditions, and comorbidity among them, in adults (aged 20+ years) during their first acute care hospitalization with a confirmed or suspected COVID-19 diagnosis in Canada. METHODS: We identified 35,519 first acute care hospitalizations with a confirmed or suspected COVID-19 diagnosis in the Discharge Abstract Database as of March 31, 2021. For each of five life-course age groups (20-34, 35-49, 50-64, 65-79, and 80+ years), we used multivariable logistic regression to examine associations between death in hospital and 30 chronic conditions, comorbidity, period of admission, and pregnant status, after adjusting for sex and age. RESULTS: About 20.9% of hospitalized patients with COVID-19 died in hospital. Conditions most strongly associated with in-hospital death varied across the life course. Chronic liver disease, other nervous system disorders, and obesity were statistically significantly associated (α = 0.05) with in-hospital death in the 20-34 to 65-79 year age groups, but the magnitude of the associations decreased as age increased. Stroke (aOR = 5.24, 95% CI: 2.63, 9.83) and other inflammatory rheumatic diseases (aOR = 4.37, 95% CI: 1.64, 10.26) were significantly associated with in-hospital death among 35 to 49 year olds only. Among 50+ year olds, more chronic conditions were significantly associated with in-hospital death, but the magnitude of the associations were generally weaker except for Down syndrome in the 50 to 64 (aOR = 8.49, 95% CI: 4.28, 16.28) and 65 to 79 year age groups (aOR = 5.19, 95% CI: 1.44, 20.91). Associations between comorbidity and death also attenuated with age. Among 20 to 34 year olds, the likelihood of death was 19 times greater (aOR = 18.69, 95% CI: 7.69, 48.24) in patients with three or more conditions compared to patients with none of the conditions, while for 80+ year olds the likelihood of death was two times greater (aOR = 2.04, 95% CI: 1.70, 2.45) for patients with six or more conditions compared to patients with none of the conditions. CONCLUSION: Conditions most strongly associated with in-hospital death among hospitalized adults with COVID-19 vary across the life course, and the impact of chronic conditions and comorbidity attenuate with age.

Associations between SARS-CoV-2 infection and incidence of new chronic condition diagnoses: a systematic review.

Because of the large number of infected individuals, an estimate of the future burdens of the long-term consequences of SARS-CoV-2 infection is needed. This systematic review examined associations between SARS-CoV-2 infection and incidence of categories of and selected chronic conditions, by age and severity of infection (inpatient vs. outpatient/mixed care). MEDLINE and EMBASE were searched (1 January 2020 to 4 October 2022) and reference lists scanned. We included observational studies from high-income OECD countries with a control group adjusting for sex and comorbidities. Identified records underwent a two-stage screening process. Two reviewers screened 50% of titles/abstracts, after which DistillerAI acted as second reviewer. Two reviewers then screened the full texts of stage one selections. One reviewer extracted data and assessed risk of bias; results were verified by another. Random-effects meta-analysis estimated pooled hazard ratios (HR). GRADE assessed certainty of the evidence. Twenty-five studies were included. Among the outpatient/mixed SARS-CoV-2 care group, there is high certainty of a small-to-moderate increase (i.e. HR 1.26-1.99) among adults ≥65 years of any cardiovascular condition, and of little-to-no difference (i.e. HR 0.75-1.25) in anxiety disorders for individuals <18, 18-64, and ≥65 years old. Among 18-64 and ≥65 year-olds receiving outpatient/mixed care there are probably (moderate certainty) large increases (i.e. HR ≥2.0) in encephalopathy, interstitial lung disease, and respiratory failure. After SARS-CoV-2 infection, there is probably an increased risk of diagnoses for some chronic conditions; whether the magnitude of risk will remain stable into the future is uncertain.

Risk of a second cancer in Canadians diagnosed with a first cancer in childhood or adolescence.

BACKGROUND: Second cancers are an adverse outcome experienced by childhood cancer survivors. We quantify the risk and correlates of a second cancer in Canadians diagnosed with a first cancer prior to age 20 years. METHODS: Using death-linked Canadian Cancer Registry data, a population-based cohort diagnosed with a first cancer between 1992 and 2014, prior to age 20 years, were followed for occurrence of a second cancer to the end of 2014. We estimate standardized incidence ratios (SIR), absolute excess risks (AER), cumulative probabilities, and hazard ratios (HR). FINDINGS: 22,635 people contributed 204,309•1 person-years of follow-up. Overall risk of a second cancer was 6•5 (95% CI: 5•8-7•1) times greater than expected resulting in an AER of 16•5 (14•4-18•5) cancers per 10,000 person-years and a 4•8% (3•8%-6•0%) cumulative probability of a second cancer at 22•6 years of follow-up. SIRs decreased with increasing age at diagnosis and time since diagnosis; were larger in more recent calendar periods of diagnosis; and varied by type of first cancer. Large SIRs in the first year after diagnosis and in those diagnosed in 2010-2014 were partly associated with changing registry practices. For the whole cohort, factors associated with the hazard of a second cancer included: being female vs. male [HR = 1•439 (95%CI: 1•179-1•760)]; being diagnosed in 2005-2014 vs. 1992-2004 [2•084 (1•598-2•719)]; having synchronous first cancers [4•814 (2•042-9•509)]; and being diagnosed with certain types of cancer. Factors varied, however, by type of first cancer. INTERPRETATION: Risks of a second cancer are not equally distributed and can be impacted by changes in registry practice and the methods used to define second cancers.

The Impact of Multiple Primary Rules on Cancer Statistics in Canada, 1992 to 2012.

INTRODUCTION: Several sets of multiple primary rules have been used in Canada to determine whether a cancer is new and little is known of the impact on cancer statistics. We examine the effect of rules on the magnitude and trend of age-standardized incidence rates (ASIRs) of cancer in Canada between 1992 and 2012. METHODS: Cancer- and sex-specific ASIRs were estimated using Canadian Cancer Registry (CCR) rules and the more conservative International Agency for Research on Cancer (IARC) rules. CCR- and IARC-based ASIRs and trends were compared using rate ratios (CCR:IARC) and joinpoint analysis, respectively. We highlight instances where CCR-based ASIRs exceed the upper 95% confidence limit of corresponding IARC-based ASIRs, as well as instances where the magnitude and/or direction of annual percent change (APC) in ASIRs differ across rules. Additionally, we examine how differences in CCR- and IARC-based estimates vary across regions. RESULTS: Between 1992 and 2012, ASIR ratios (CCR:IARC) for all cancers combined increased from about 1 to 1.061 and 1.067 for males and females, respectively, and reached as high as 1.141 for male melanoma and 1.109 for female breast cancer. Between 2010 and 2012, ASIR ratios were elevated for stage 0-1 colorectal (males, 1.060; females, 1.072) and lung and bronchus cancer (males, 1.052; females, 1.061) and all stages of female breast cancer (stage 0-1, 1.100; stage 2, 1.061; stage 3, 1.059; stage 4, 1.094). Where differences existed, CCR-based trends tended to demonstrate steeper increases (eg, male and female melanoma) or less steep declines (eg, all male cancers, female breast cancer). Ontario was particularly impacted and substantially influenced national estimates. CONCLUSION: Multiple primary rules can substantially affect the magnitude and trend of ASIRs. The impact will continue to grow as the number of people surviving cancer, and thus at risk for subsequent cancers, continues to grow. Because of inconsistencies in the multiple primary rules used over time, we recommend using IARC rules for monitoring trends and making comparisons across jurisdictions, and using CCR rules for quantifying the full burden of cancer.

Case-Completeness of Nonmalignant Central Nervous System Tumors in the Canadian Cancer Registry, 2011-2015.

INTRODUCTION: The public health burden of nonmalignant central nervous system tumors (NMCNSTs) in Canada is unclear because casefinding and registration have historically been incomplete. The primary objective of this study is to quantify case-completeness of NMCNSTs in the Canadian Cancer Registry (CCR) using US Surveillance, Epidemiology and End Results Program (SEER) rates as the standard. METHODS: Counts, distributions, and age-standardized incidence rates (ASIRs) for malignant central nervous system tumors (MCNSTs) and NMCNSTs by sex, age, site, histology, tumor size, World Health Organization (WHO) grade, and year of diagnosis were estimated for the United States and Canada (excluding Quebec) for the time period 2011-2015 using SEER and CCR data, respectively. Canadian and provincial standardized incidence ratios (SIRs) were also calculated by sex, age, site, histology and year of diagnosis using SEER rates as the standard. Under the assumptions of high NMCNST case-completeness in SEER registries and comparable population-based rates in the United States and Canada, SIRs less than 100% suggest incomplete case registration. RESULTS: Between 2011 and 2015, the ASIR for MCNSTs is similar in the United States (6.97 per 100,000 persons; 95% CI, 6.89-7.05), Canada (7.11 per 100,000; 95% CI, 6.97-7.24), and across provinces (range, 6.53-7.35 per 100,000). Conversely, the ASIR for NMCNSTs is 1.61 times greater in the United States (17.15 per 100,000; 95% CI, 17.02-17.27) than Canada (10.65 per 100,000; 95% CI, 10.49-10.82). SIRs for NMCNSTs range from 22.5% (95% CI, 15.6%-31.5%) in Prince Edward Island to 85.3% (95% CI, 83.7%-86.9%) in Ontario and vary by demographics, tumor characteristics, and year. Identified data limitations include nonspecific tumor characteristics and potential misclassification. CONCLUSION: NMCNST surveillance in Canada is compromised by incomplete case registration and data quality limitations. Enhancement of case ascertainment processes for these tumors, which may be diagnosed radiologically, may be warranted.

Cancers attributable to excess body weight in Canada in 2010. / Cancers attribuables à l'excès de poids au Canada en 2010.

INTRODUCTION: Excess body weight (body mass index [BMI] ≥ 25.00 kg/m2) is an established risk factor for diabetes, hypertension and cardiovascular disease, but its relationship to cancer is lesser-known. This study used population attributable fractions (PAFs) to estimate the cancer burden attributable to excess body weight in Canadian adults (aged 25+ years) in 2010. METHODS: We estimated PAFs using relative risk (RR) estimates from the World Cancer Research Fund International Continuous Update Project, BMI-based estimates of overweight (25.00 kg/m2-29.99 kg/m2) and obesity (30.00+ kg/m2) from the 2000-2001 Canadian Community Health Survey, and cancer case counts from the Canadian Cancer Registry. PAFs were based on BMI corrected for the bias in self-reported height and weight. RESULTS: In Canada in 2010, an estimated 9645 cancer cases were attributable to excess body weight, representing 5.7% of all cancer cases (males 4.9%, females 6.5%). When limiting the analysis to types of cancer associated with high BMI, the PAF increased to 14.9% (males 17.5%, females 13.3%). Types of cancer with the highest PAFs were esophageal adenocarcinoma (42.2%), kidney (25.4%), gastric cardia (20.7%), liver (20.5%), colon (20.5%) and gallbladder (20.2%) for males, and esophageal adenocarcinoma (36.1%), uterus (35.2%), gallbladder (23.7%) and kidney (23.0%) for females. Types of cancer with the greatest number of attributable cases were colon (1445), kidney (780) and advanced prostate (515) for males, and uterus (1825), postmenopausal breast (1765) and colon (675) for females. Irrespective of sex or type of cancer, PAFs were highest in the Prairies (except Alberta) and the Atlantic region and lowest in British Columbia and Quebec. CONCLUSION: The cancer burden attributable to excess body weight is substantial and will continue to rise in the near future because of the rising prevalence of overweight and obesity in Canada.

INTRODUCTION: L'excès de poids (indice de masse corporelle [IMC] de 25,00 kg/m2 ou plus) est un facteur de risque bien connu de diabète, d'hypertension et de maladie cardiovasculaire, mais on en sait moins sur son lien avec le cancer. Dans cette étude, nous avons utilisé le risque attribuable dans la population (RAP) pour estimer le fardeau des cancers attribuables à l'excès de poids chez les adultes canadiens (de 25 ans ou plus) en 2010. MÉTHODOLOGIE: Nous avons estimé les RAP en utilisant des estimations du risque relatif (RR) tirées du Continuous Update Project du World Cancer Research Fund International, des estimations du surpoids et de l'obésité fondées sur l'IMC tirées de l'Enquête sur la santé dans les collectivités canadiennes de 2000-2001 (surpoids : 25,00 à 29,99 kg/m2; obésité : 30,00 kg/m2 et plus) et nous avons utilisé les nombres de cas de cancer figurant dans le Registre canadien du cancer. Les RAP ont été fondés sur des IMC corrigés pour tenir compte du biais associé à l'autodéclaration de la taille et du poids. RÉSULTATS: Au Canada, en 2010, on peut attribuer environ 9 645 cas de cancer à un excès de poids, ce qui représente 5,7 % de tous les cas de cancer (hommes : 4,9 %; femmes : 6,5 %). En limitant l'analyse aux types de cancer associés à un IMC élevé, le RAP augmente à 14,9 % (hommes : 17,5 %; femmes : 13,3 %). Les types de cancer pour lesquels le RAP était le plus élevé étaient l'adénocarcinome de l'oesophage (42,2 %), le cancer du rein (25,4 %), le cancer du cardia (20,7 %), le cancer du foie (20,5 %), le cancer du côlon (20,5 %) et le cancer de la vésicule biliaire (20,2 %) chez les hommes, et l'adénocarcinome de l'oesophage (36,1 %), le cancer de l'utérus (35,2 %), le cancer de la vésicule biliaire (23,7 %) et le cancer du rein (23,0 %) chez les femmes. Les types de cancer pour lesquels le nombre de cas attribuables était le plus élevé étaient le cancer du côlon (1 445), le cancer du rein (780) et le cancer de la prostate à un stade avancé (515) chez les hommes, et le cancer de l'utérus (1 825), le cancer du sein postménopausique (1 765) et le cancer du côlon (675) chez les femmes. Quels que soient le sexe et le type de cancer, les RAP étaient les plus élevés dans les Prairies (sauf en Alberta) et la région de l'Atlantique, et les plus faibles en Colombie-Britannique et au Québec. CONCLUSION: Le fardeau du cancer attribuable à l'excès de poids est considérable et continuera de croître à court terme en raison de la hausse de la prévalence du surpoids et de l'obésité au Canada.

Randomized controlled trial of a telephone intervention by nurses to provide information and support to patients and their partners after elective coronary artery bypass graft surgery: effects of anxiety.

OBJECTIVE: The purpose of this study was to determine the effectiveness of an information and support telephone intervention for reducing anxiety in patients who have undergone coronary artery bypass graft surgery and their partners. DESIGN: The study is a randomized controlled trial. Intervention began at discharge; 6 telephone calls were made to patients and partners over 7 weeks. Primary outcome was Beck Anxiety Inventory measured at baseline in hospital, at home on day 3, week 4, and week 8. SAMPLE: The subjects were 131 patients who have undergone elective coronary artery bypass graft surgery and their partners. RESULTS: Patients' anxiety was moderate to severe the day before discharge. It was significantly lower in the treatment group than in the control group at day 2 at home. Partners always had lower anxiety than patients. A more sustained decrease in anxiety in the partner treatment group was found at both day 2 and week 4. CONCLUSION: Intervention effect is in the early period after discharge-- the time most affected by reduced lengths of stay.

Rates of carpal tunnel syndrome, epicondylitis, and rotator cuff claims in Ontario workers during 1997.

The primary objective of this research was the calculation of crude and specific rates of first-allowed, lost-time carpal tunnel syndrome (CTS), epicondylitis, and rotator cuff syndrome/tear (RCS/RCT) claims in Ontario workers during 1997. A secondary objective was to determine if results related to these diagnoses were consistent with findings for all cumulative trauma disorders affecting the specific part of upper extremity region. Rates were calculated by combining claim counts and population "at-risk" estimates derived from the Ontario Workplace Safety and Insurance Board databases and Canadian Labour Force Survey, respectively. The prevention index was used to prioritize occupations for intervention. Gender-specific rates declined as one moved proximally along the upper extremity. Similarly, female to male claim rate ratios declined from 1.61 for CTS to 0.47 for RCS/RCT. Frequently occurring highest rate and prevention index occupational categories across gender and diagnoses included "textiles, furs & leathergoods" and "other machining occupations". Diagnosis-specific findings were consistent with previously reported part of upper extremity findings.

Work-related cumulative trauma disorders of the upper extremity: navigating the epidemiologic literature.

BACKGROUND: Cumulative trauma disorder of the upper extremity (CTDUE) is an umbrella term used to describe disorders resulting from repeated use of the upper extremity over time rather than a specific incident. The primary purpose of this article is to summarize the literature regarding the rate of work-related CTDUE, while drawing attention to the various factors contributing to the wide range of reported findings. METHODS: The Cumulative Index to Nursing and Allied Health and Medline databases were searched for articles focusing on etiology or rates of occurrence of work-related CTDUE and their findings were summarized. RESULTS: Potential reasons for rising rates, a gender differential, and the substantial range in rates and rate ratios are delineated and important factors to consider when interpreting rates derived from workers' compensation data are detailed. CONCLUSIONS: Future research should attempt to correctly identify more specific categories of CTDUE in well-defined and accurately-quantified "at risk" populations to provide more meaningful information regarding the epidemiology of CTDUE and the effectiveness of control activities.

Estimating the population at risk for Ontario Workplace Safety and Insurance Board-covered injuries or diseases.

Difficulty in quantifying the population at risk for a work-related injury or disease limits the usefulness of workers' compensation data for surveillance. This article presents a method of obtaining estimates of the Ontario Workplace Safety and Insurance Board (OWSIB)- covered workforce using the Canadian Labour Force Survey (LFS). The method involves extracting that class of worker most likely to be insured by the OWSIB and using actual hours worked to estimate full-time equivalents at risk. Compared to population at risk estimates readily available from published tables, the refined crude estimate was 26% lower and ranged from 15 to 79% lower depending on the age group. The percentage decrease from published estimates was generally greater for women compared to men, particularly in the 25 to 39 year age categories. Consequently, the method of deriving population at risk estimates should be considered when comparing rates across sexes, ages, industries or occupations.

Rates of claims for cumulative trauma disorder of the upper extremity in Ontario workers during 1997.

Surveillance of work-related cumulative trauma disorder of the upper extremity (CTDUE) requires valid and reliable claim extraction strategies and should examine for confounding and interaction. This research estimated crude and specific rates of CTDUE claims in Ontario workers during 1997 while acknowledging misclassification and testing for confounding and interaction. Lower and upper limit event estimates were obtained by means of an algorithm applied to the Ontario Workplace Safety and Insurance Board (OWSIB) database and were combined with "at-risk" estimates obtained from the Canadian Labour Force Survey (LFS). Poisson regression was used to evaluate confounding and interaction. The method used to identify CTDUE claims had a substantial impact on the magnitude of rates, female to male rate ratios, the most commonly affected part of the upper extremity and the highest risk occupational categories. Poisson regression identified sex interactions. It allowed rigorous evaluation of the data and indicated that rates should be examined separately for men and women. Researchers should clearly define extraction strategies and examine the impact of misclassification.

Identifying cumulative trauma disorders of the upper extremity in workers' compensation databases.

BACKGROUND: Impeding the use of workers' compensation databases for surveillance of cumulative trauma disorder of the upper extremity (CTDUE) is the lack of valid and reliable extraction strategies. METHODS: Using the Z795-96 Coding of Work Injury or Disease Information standard, an algorithm was developed to classify claims as definite, possible, or non-CTDUE. Reliability was assessed with standardized claim reviews. RESULTS: Moderate to substantial agreement (Kappa = 0.48, 95% CI 0.42-0.54, n = 328; weighted Kappa = 0.75, 95% CI 0.70-0.80, n = 328) was demonstrated. The algorithm produced relatively homogeneous groups of definite and non-CTDUE claims but 29.1% of the possible CTDUE claims were categorized as definite CTDUE by claim review. Part of body agreement was almost perfect (Kappa = 0.81-1.00) when determining whether the upper extremity or specific parts of the upper extremity were involved. CONCLUSIONS: The algorithm can be used to estimate the number of CTDUE and extract homogeneous groups of definite and non-CTDUE claims. Furthermore, certain upper extremity part of body codes can be used to target anatomically defined claims.