Quantifying cancer risk from exposures to medical imaging in the Risk of Pediatric and Adolescent Cancer Associated with Medical Imaging (RIC) Study: research methods and cohort profile.

PURPOSE: The Risk of Pediatric and Adolescent Cancer Associated with Medical Imaging (RIC) Study is quantifying the association between cumulative radiation exposure from fetal and/or childhood medical imaging and subsequent cancer risk. This manuscript describes the study cohorts and research methods. METHODS: The RIC Study is a longitudinal study of children in two retrospective cohorts from 6 U.S. healthcare systems and from Ontario, Canada over the period 1995-2017. The fetal-exposure cohort includes children whose mothers were enrolled in the healthcare system during their entire pregnancy and followed to age 20. The childhood-exposure cohort includes children born into the system and followed while continuously enrolled. Imaging utilization was determined using administrative data. Computed tomography (CT) parameters were collected to estimate individualized patient organ dosimetry. Organ dose libraries for average exposures were constructed for radiography, fluoroscopy, and angiography, while diagnostic radiopharmaceutical biokinetic models were applied to estimate organ doses received in nuclear medicine procedures. Cancers were ascertained from local and state/provincial cancer registry linkages. RESULTS: The fetal-exposure cohort includes 3,474,000 children among whom 6,606 cancers (2394 leukemias) were diagnosed over 37,659,582 person-years; 0.5% had in utero exposure to CT, 4.0% radiography, 0.5% fluoroscopy, 0.04% angiography, 0.2% nuclear medicine. The childhood-exposure cohort includes 3,724,632 children in whom 6,358 cancers (2,372 leukemias) were diagnosed over 36,190,027 person-years; 5.9% were exposed to CT, 61.1% radiography, 6.0% fluoroscopy, 0.4% angiography, 1.5% nuclear medicine. CONCLUSION: The RIC Study is poised to be the largest study addressing risk of childhood and adolescent cancer associated with ionizing radiation from medical imaging, estimated with individualized patient organ dosimetry.

Leukemia Risk in a Cohort of 3.9 Million Children with and without Down Syndrome.

OBJECTIVE: To assess leukemia risks among children with Down syndrome in a large, contemporary cohort. STUDY DESIGN: Retrospective cohort study including 3 905 399 children born 1996-2016 in 7 US healthcare systems or Ontario, Canada, and followed from birth to cancer diagnosis, death, age 15 years, disenrollment, or December 30, 2016. Down syndrome was identified using International Classification of Diseases, Ninth and Tenth Revisions, diagnosis codes. Cancer diagnoses were identified through linkages to tumor registries. Incidence and hazard ratios (HRs) of leukemia were estimated for children with Down syndrome and other children adjusting for health system, child's age at diagnosis, birth year, and sex. RESULTS: Leukemia was diagnosed in 124 of 4401 children with Down syndrome and 1941 of 3 900 998 other children. In children with Down syndrome, the cumulative incidence of acute myeloid leukemia (AML) was 1405/100 000 (95% CI 1076-1806) at age 4 years and unchanged at age 14 years. The cumulative incidence of acute lymphoid leukemia in children with Down syndrome was 1059/100 000 (95% CI 755-1451) at age 4 and 1714/100 000 (95% CI 1264-2276) at age 14 years. Children with Down syndrome had a greater risk of AML before age 5 years than other children (HR 399, 95% CI 281-566). Largest HRs were for megakaryoblastic leukemia before age 5 years (HR 1500, 95% CI 555-4070). Children with Down syndrome had a greater risk of acute lymphoid leukemia than other children regardless of age (<5 years: HR 28, 95% CI 20-40, ≥5 years HR 21, 95% CI 12-38). CONCLUSIONS: Down syndrome remains a strong risk factor for childhood leukemia, and associations with AML are stronger than previously reported.

Medical Immunosuppression and Outcomes in Cutaneous Melanoma: A Population-Based Cohort Study.

BACKGROUND: Melanoma and the immune system are intimately related. However, the association of immunosuppressive medications (ISMs) with survival in melanoma is not well understood. The study evaluated this at a population level. METHODS: A cohort of patients with a diagnosis of invasive cutaneous melanoma (2007-2015) was identified from the Ontario Cancer Registry and linked to identify demographics, stage at diagnosis, prescription of immunosuppressive medications (both before and after diagnosis), and outcomes. The demographics of patients with and without prescriptions for ISM were compared. Patients eligible for Ontario's Drug Benefit Plan were included to ensure accurate prescription data. The primary outcome was overall survival. Cox Proportional Hazards Regression models identified factors associated with mortality, including use of ISM as a time-varying covariate. RESULTS: Of the 4954 patients with a diagnosis of cutaneous melanoma, 1601 had a prescription for ISM. The median age of the patients was 74 years. Overall, 58.4% of the patients were men (60.5% of those without ISM and 54% of those using ISM; p < 0.001). The use of oral immunosuppression was associated with an increased hazard of death (hazard ratio, 5.84; 95% confidence interval, 5.11-6.67; p < 0.0001) when control was used for age, disease stage at diagnosis, anatomic site, comorbidity, and treatment. Other factors associated with death were increasing age, male sex, increased disease stage, truncal location of primary melanoma, and inadequate treatment. In sensitivity analysis with steroid-only ISM use excluded, survival did not differ significantly (p = 0.355). CONCLUSIONS: The use of immunosuppressive steroids for melanoma is associated with worse overall survival. Use of steroids should be limited when possible.

Outcomes of Immunosuppressed Patients Who Develop Melanoma: A Population-Based Propensity-Matched Cohort Study.

INTRODUCTION: Few studies have examined outcomes in immunosuppressed patients who develop melanoma. The purpose of this study is to compare survival in immunosuppressed patients who developed melanoma with that in patients with melanoma who are not immunosuppressed. METHODS: Immunosuppressed patients were defined as having solid organ transplant, lymphoma, leukemia, or human immunodeficiency virus prior to diagnosis of melanoma. Patients with cutaneous melanoma with and without immunosuppression were identified retrospectively from the Ontario Cancer Registry (2007-2015) and linked with administrative databases to identify demographics, treatment, and outcomes. Immunosuppressed patients were matched with non-immunosuppressed patients based on age at diagnosis, sex, birth year, stage at diagnosis, and propensity score. The primary outcome was overall survival. Multivariable Cox proportional hazard regression was used to identify factors associated with survival. RESULTS: Baseline characteristics were well balanced in 218 immunosuppressed patients matched to 436 controls. Of the patients, 186 (28.4%) were female, and median age at melanoma diagnosis was 69 (interquartile range, IQR 59-78) years. Three-year overall survival (OS) was 65% for immunosuppressed patients and 79% for non-immunosuppressed patients. Melanoma was the leading cause of death for both groups. On multivariable analysis, immunosuppression was associated with increased mortality [hazard ratio (HR) 1.70, 95% confidence interval (CI) 1.30-2.23]. Adequate treatment (HR 0.36, 95% CI 0.22-0.58) and dermatologist visits either before (HR 0.52, 95% CI 0.36-0.73) or after (HR 0.61, 95% CI 0.41-0.90) melanoma diagnosis were associated with improved OS. CONCLUSIONS: Immunosuppressed patients who develop melanoma have worse outcomes when matched to non-immunosuppressed patients. This decrease in survival appears related to the underlying condition rather than diagnosis of melanoma.

Class III Obesity and Other Factors Associated with Longer Wait Times for Endometrial Cancer Surgery: A Population-Based Study.

OBJECTIVE: To evaluate the impact of class III obesity (body mass index >40 kg/m2) on wait times for endometrial cancer surgery in Ontario, as well as other factors that influence wait time. METHODS: We performed a population-based cross-sectional study evaluating diagnosis-to-surgery time for women with endometrioid adenocarcinoma of the endometrium, during the period of 2006 to 2015, using linked administrative databases. Wait time differences between women with and without class III obesity were evaluated using a Wilcoxon rank-sum test. A multivariable generalized linear model under a generalized estimating equations approach was used to evaluate patient factors (i.e., obesity, age, comorbidities, marginalization, recent immigration, diagnosis year, geographic location), tumour characteristics (i.e., grade, stage), provider type (i.e., surgeon specialty), and institutional characteristics (i.e., rurality, hysterectomy volume, availability of minimally invasive surgery) that influence wait times. RESULTS: In total, 9797 women met the criteria for inclusion; 2171 (22%) had class III obesity. The overall median wait time was 55 days (interquartile range [IQR] 37-77 d) and the median wait time was significantly longer for women with class III obesity (62 [IQR 43-88] vs. 53 [IQR 36-74] d, standardized mean difference, 0.30). Age <40 or >70 years, comorbidities, lower-grade disease, surgery at an urban teaching hospital, and surgery at a high-volume hospital with greater availability of minimally invasive surgery were associated with longer wait times. After adjusting for these variables, women with class III obesity waited 12% longer. CONCLUSION: Class III obesity, comorbidities, and older age are associated with a longer diagnosis-to-surgery time. As the prevalence of obesity and endometrial cancer rise, processes are needed to promote equitable, timely access to care.

Economic Analysis of Adjuvant Chemoradiotherapy Compared with Chemotherapy in Resected Pancreas Cancer.

BACKGROUND: Population-based survival and costs of pancreas adenocarcinoma patients receiving adjuvant chemoradiation and chemotherapy following pancreaticoduodenectomy are poorly understood. METHODS: This retrospective cohort study used linked administrative and pathological datasets to identify all patients diagnosed with pancreas adenocarcinoma and undergoing pancreaticoduodenectomy in Ontario between April 2004 and March 2014, who received postoperative chemoradiation or chemotherapy. Stage and margin status were defined by using pathology reports. Kaplan-Meier and Cox proportional hazards regression survival analyses were used to determine associations between adjuvant treatment approach and survival, while stratifying by margin status. Median overall health system costs were calculated at 1 and 3 years for chemoradiation and chemotherapy, and differences were tested using the Kruskal-Wallis test. RESULTS: Among 709 patients undergoing pancreaticoduodenectomy for pancreas cancer during the study period, the median survival was 21 months. Median survival was 19 months for chemoradiation and 22 months for chemotherapy. Patients receiving chemoradiation were more likely to have positive margins: 47.7% compared with 19.2% in chemotherapy. After stratifying by margin status and controlling for confounders, adjusted hazard ratio of death were not statistically different between chemotherapy and chemoradiation [margin positive, hazard ratio (HR) = 0.99, 95% confidence interval (CI) = 0.88-1.27; margin negative, HR 0.95, 95% CI 0.91-1.18]. Overall 1-year health system costs were significantly higher for chemoradiation (USD $70,047) than chemotherapy (USD $54,005) (p ≤ 0.001). CONCLUSIONS: Chemotherapy and chemoradiation yielded similar survival, but chemoradiation resulted in higher costs. To create more sustainable healthcare systems, both the efficacy and costs of therapies should be considered.

Trends in Use of Medical Imaging in US Health Care Systems and in Ontario, Canada, 2000-2016.

Importance: Medical imaging increased rapidly from 2000 to 2006, but trends in recent years have not been analyzed. Objective: To evaluate recent trends in medical imaging. Design, Setting, and Participants: Retrospective cohort study of patterns of medical imaging between 2000 and 2016 among 16 million to 21 million patients enrolled annually in 7 US integrated and mixed-model insurance health care systems and for individuals receiving care in Ontario, Canada. Exposures: Calendar year and country (United States vs Canada). Main Outcomes and Measures: Use of computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, and nuclear medicine imaging. Annual and relative imaging rates by imaging modality, country, and age (children [<18 years], adults [18-64 years], and older adults [≥65 years]). Results: Overall, 135 774 532 imaging examinations were included; 5 439 874 (4%) in children, 89 635 312 (66%) in adults, and 40 699 346 (30%) in older adults. Among adults and older adults, imaging rates were significantly higher in 2016 vs 2000 for all imaging modalities other than nuclear medicine. For example, among older adults, CT imaging rates were 428 per 1000 person-years in 2016 vs 204 per 1000 in 2000 in US health care systems and 409 per 1000 vs 161 per 1000 in Ontario; for MRI, 139 per 1000 vs 62 per 1000 in the United States and 89 per 1000 vs 13 per 1000 in Ontario; and for ultrasound, 495 per 1000 vs 324 per 1000 in the United States and 580 per 1000 vs 332 per 1000 in Ontario. Annual growth in imaging rates among US adults and older adults slowed over time for CT (from an 11.6% annual percentage increase among adults and 9.5% among older adults in 2000-2006 to 3.7% among adults in 2013-2016 and 5.2% among older adults in 2014-2016) and for MRI (from 11.4% in 2000-2004 in adults and 11.3% in 2000-2005 in older adults to 1.3% in 2007-2016 in adults and 2.2% in 2005-2016 in older adults). Patterns in Ontario were similar. Among children, annual growth for CT stabilized or declined (United States: from 10.1% in 2000-2005 to 0.8% in 2013-2016; Ontario: from 3.3% in 2000-2006 to -5.3% in 2006-2016), but patterns for MRI were similar to adults. Changes in annual growth in ultrasound were smaller among adults and children in the United States and Ontario compared with CT and MRI. Nuclear medicine imaging declined in adults and children after 2006. Conclusions and Relevance: From 2000 to 2016 in 7 US integrated and mixed-model health care systems and in Ontario, rates of CT and MRI use continued to increase among adults, but at a slower pace in more recent years. In children, imaging rates continued to increase except for CT, which stabilized or declined in more recent periods. Whether the observed imaging utilization was appropriate or was associated with improved patient outcomes is unknown.

Melanoma patterns of care in Ontario: A call for a strategic alignment of multidisciplinary care.

BACKGROUND AND OBJECTIVES: Variability in melanoma management has prompted concerns about equitable and timely treatment. We investigated patterns of melanoma diagnosis and treatment using population-level data. METHODS: Patients with invasive cutaneous melanoma were identified retrospectively from the Ontario Cancer Registry (2003-2012) and deterministically linked with administrative databases to identify incidence, disease characteristics, geographic origin, and multimodal treatment within a year of diagnosis. Melanoma treatment was categorized as inadequate or adequate based on multidisciplinary clinical algorithms. Multivariable logistic regression was used to model factors associated with treatment adequacy. RESULTS: From 2003 to 2012, 22 918 patients with invasive melanoma were identified with annual age/sex standardized incidence rates of 11.7-14.3/100 000 for females and 13.4-15.9/100 000 for males. Melanoma occurred at median age of 62 and primarily on extremities (43.9%). Within 1 year after diagnosis, 86.7% of patients received surgery as primary therapy. A total of 2312 (10.6%) patients received inadequate or no treatment after diagnosis. Receiving adequate treatment was associated with consultation with dermatology (OR 1.92, CI 1.71-2.14), plastic surgery (OR 4.80, CI 4.32-5.34), or general surgery (OR 2.15, CI 1.94-2.38). CONCLUSIONS: Significant variation exists in melanoma management and nearly one in nine patients is inadequately treated. Referral to sub-specialized providers is critical for ensuring appropriate care.

Cervical cancer screening uptake among HIV-positive women in Ontario, Canada: A population-based retrospective cohort study.

Cervical cancer caused by oncogenic types of the human papillomavirus (HPV) is of concern among HIV-positive women due to impairment of immune responses required to control HPV infection. Our objectives were to describe patterns of cervical cancer screening using Pap cytology testing among HIV-positive women in Ontario, Canada from 2008 to 2013 and to identify factors associated with adequate screening. We conducted a retrospective, population-based cohort study among screen-eligible HIV-positive women using provincial administrative health data. We estimated annual proportions tested and reported these with 95% confidence intervals (CI). Next, using person-years as the unit of analysis, we identified factors associated with annual Pap testing using log-binomial regression. A total of 2271 women were followed over 10,697 person-years. In 2008, 34.0% (95%CI 31.1-37.0%) had a Pap test. By 2013, the proportion of HIV-positive women tested was 25.9% (95%CI 23.6-28.2%). Women who were most likely to undergo testing were younger, were immigrants from countries with generalized HIV epidemics, lived in the highest income neighbourhoods, had a female primary care physician, had two or more encounters per year with an infectious disease or internal medicine specialist, and had greater comorbidity. Nearly three in four HIV-positive women were under-screened despite all having universal insurance for medically-necessary services. Annual Pap testing decreased following the 2011-2013 release of new guidelines for a lengthened screen interval for average risk women and a billing disincentive. Clinic-based intervention such as physician alerts or reminders may be needed to improve screening coverage among HIV-positive women.

Retrospective assessment of the quality of diabetes care in a rural diabetes clinic in Western Kenya.

BACKGROUND: Sub-Saharan Africa continues to face the highest rate of mortality from diabetes in the world due to limited access to quality diabetes care. We assessed the quality of diabetes care in a rural diabetes clinic in western Kenya. METHODS: To provide a comprehensive assessment, a set of clinical outcomes, process, and structure metrics were evaluated to assess the quality of diabetes care provided in the outpatient clinic at Webuye District Hospital. The primary clinical outcome measures were the change in HbA1c and point of care blood glucose. In assessing process metrics, the primary measure was the percentage of patients who were lost to follow up. The structure metrics were assessed by evaluating different facets of the operation of the clinic and their accordance with the International Diabetes Federation (IDF) guidelines. RESULTS: A total of 524 patients were enrolled into the diabetes clinic during the predefined period of evaluation. The overall clinic population demonstrated a statistically significant reduction in HbA1c and point of care blood glucose at all time points of evaluation after baseline. Patients had a mean baseline HbA1C of 10.2% which decreased to 8.4% amongst the patients who remained in care after 18 months. In terms of process measures, 38 patients (7.3%) were characterized as being lost to follow up as they missed clinic visits for more than 6 months. Through the assessment of structural metrics, the clinic met at least the minimal standards of care for 14 out of the 19 domains recommended by the IDF. CONCLUSION: This analysis illustrates the gains made in various elements of diabetes care quality which can be used by other programs to guide diabetes care scale up across the region.

Primary care utilization in people who experience imprisonment in Ontario, Canada: a retrospective cohort study.

BACKGROUND: Access to primary care is an important determinant of health, and data are sparse on primary care utilization for people who experience imprisonment. We aimed to describe primary care utilization for persons released from prison, and to compare utilization with the general population. METHODS: We linked correctional data for all persons released from provincial prison in Ontario, Canada in 2010 with health administrative data. We matched each person by age and sex with four general population controls. We compared primary care utilization rates using generalized estimating equations. We adjusted rate ratios for aggregated diagnosis groups, to explore this association independent of comorbidity. We examined the proportion of people using primary care using chi squared tests and time to first primary care visit post-release using the Kaplan-Meier method. RESULTS: Compared to the general population controls, the prison release group had significantly increased relative rates of primary care utilization: at 6.1 (95% CI 5.9-6.2) in prison, 3.7 (95% CI 3.6-3.8) in the week post-release and between 2.4 and 2.6 in the two years after prison release. All rate ratios remained significantly increased after adjusting for comorbidity. In the month after release, however, 66.3% of women and 75.5% of men did not access primary care. CONCLUSIONS: Primary care utilization is high in prison and post-release for people who experience imprisonment in Ontario, Canada. Increased use is only partly explained by comorbidity. The majority of people do not access primary care in the month after prison release. Future research should identify reasons for increased use and interventions to improve care access for persons who are not accessing care post-release.

Global disparities in cystic fibrosis outcomes prior to CFTR modulators: A CF registries cohort study in South Africa and Canada.

BACKGROUND: Outcomes of cystic fibrosis (CF) differ between low-middle income and high-income countries, but comparative data are lacking. We compared South African (SA) and Canadian CF outcomes to explore what disparities existed prior to access of CFTR modulators in Canada. METHODS: A cross-sectional study of SA and Canadian CF registries data for period 1 January to 31 December 2018. CF registry data were harmonised between countries to compare lung function and nutrition outcomes. Poor nutrition was defined as BMIz-score < -1 in children and < 18.5 kg/m2 in adults. Standardised mean difference (SMD) >10 was considered significant. RESULTS: After excluding Canadians on CFTR modulators and lung transplant recipients, data on 4049 Canadian and 446 SA people was analysed. Compared to Canada, people in SA were younger (median age 15.8 years vs. 24.1 years: SMD 52) with fewer males (47.8% vs 54.2%; SMD 12.5) and White (70.9% vs. 93.3%; SMD 61.3). Class I-III CFTR mutation frequency was similar in SA (n = 384, 86.1%) and Canada (n = 3426, 84.9%). After adjusting for age, gender, diagnosis age, genotype, P.aeruginosa infection and pulmonary treatments, FEV1pp was 8.9% lower (95% CI 6.3% to 11.4%) and poor nutrition 1.7-fold more common (OR 1.70; 95% CI 1.19-2.41) in SA compared to Canada. CONCLUSION: Lung function and nutrition was significantly lower in SA compared to Canada. Global disparities in CF outcomes between high and low-middle income countries are likely to widen as CFTR modulators are rapidly scaled up in only high-income countries.

Measuring the burden of cystic fibrosis: A scoping review.

BACKGROUND: Cystic fibrosis (CF) contributes a significant economic burden on individuals, healthcare systems, and society. Understanding the economic impact of CF is crucial for planning resource allocation. METHODS: We conducted a scoping review of literature published between 1990 and 2022 that reported the cost of illness, and/or economic burden of CF. Costs were adjusted for inflation and reported as United States dollars. RESULTS: A total of 39 studies were included. Direct healthcare costs (e.g., medications, inpatient and outpatient care) were the most frequently reported. Most studies estimated the cost of CF using a prevalence-based (n = 18, 46.2 %), bottom-up approach (n = 23, 59 %). Direct non-healthcare costs and indirect costs were seldom included. The most frequently reported direct cost components were medications (n = 34, 87.2 %), inpatient care (n = 33, 84.6 %), and outpatient care (n = 31, 79.5 %). Twenty-eight percent (n = 11) of studies reported the burden of CF from all three perspectives (healthcare system (payer), individual, and society). Indirect costs of CF were reported in approximately 20 % of studies (n = 8). The reported total cost of CF varied widely, ranging from $451 to $160,000 per person per year (2022 US$). The total cost depended on the number of domains and perspectives included in each study. CONCLUSIONS: Most studies only reported costs to the healthcare system (i.e., hospitalizations and healthcare encounters) which likely underestimates the total costs of CF. The wide range of costs reported highlights the importance of standardizing perspectives, domains and costs when estimating the economic burden of CF.

Matching Special Olympics registration data with administrative health databases: Feasibility and health status differences in children and youth with IDD.

BACKGROUND: Children and youth with intellectual and developmental disabilities (IDD) experience health disparities. What is unknown is if data collected from children and youth with IDD who participate in Special Olympics is representative of children and youth with IDD who do not. OBJECTIVES: Aim 1: determine the feasibility of matching a database of registrants from Special Olympics Ontario (SOO), with population-based health services databases in Ontario, Canada housed at ICES. Aim 2: evaluate the differences between the database sources with regards to demographic variables and clinical status. METHODS: Using deterministic and probabilistic matching, registration data from SOO were matched to administrative health databases. Established algorithms were used to determine the prevalence of asthma, diabetes, and mental disorder in addition to demographic variables. RESULTS: The matching rate was over 90%; 8404 were attributed to children and youth between the ages of 0-19 years. When comparing SOO participants with IDD to non-SOO participants with IDD, children and youth who participate in SOO were, on average, older with no further differences between groups on clinical or demographic variables. When comparing those previously not identified in the health services databases (from SOO) to those with IDD identified by ICES, the SOO participants appear to use the health system less, possibly indicating a better health status. CONCLUSIONS: Research conducted on child and youth who participate in Special Olympics Ontario can be generalized to the broader population of children and youth with IDD in Canada when adjusted for age; however, care should be taken when comparing levels of overall morbidity.

Factors associated with clinical progression to severe COVID-19 in people with cystic fibrosis: A global observational study.

BACKGROUND: This international study aimed to characterise the impact of acute SARS-CoV-2 infection in people with cystic fibrosis and investigate factors associated with severe outcomes. Methods Data from 22 countries prior to 13th December 2020 and the introduction of vaccines were included. It was de-identified and included patient demographics, clinical characteristics, treatments, outcomes and sequalae following SARS-CoV-2 infection. Multivariable logistic regression was used to investigate factors associated with clinical progression to severe COVID-19, using the primary outcome of hospitalisation with supplemental oxygen. RESULTS: SARS-CoV-2 was reported in 1555 people with CF, 1452 were included in the analysis. One third were aged <18 years, and 9.4% were solid-organ transplant recipients. 74.5% were symptomatic and 22% were admitted to hospital. In the non-transplanted cohort, 39.5% of patients with ppFEV1<40% were hospitalised with oxygen verses 3.2% with ppFEV >70%: a 17-fold increase in odds. Worse outcomes were independently associated with older age, non-white race, underweight body mass index, and CF-related diabetes. Prescription of highly effective CFTR modulator therapies was associated with a significantly reduced odds of being hospitalised with oxygen (AOR 0.43 95%CI 0.31-0.60 p<0.001). Transplanted patients were hospitalised with supplemental oxygen therapy (21.9%) more often than non-transplanted (8.8%) and was independently associated with the primary outcome (Adjusted OR 2.45 95%CI 1.27-4.71 p=0.007). CONCLUSIONS: This is the first study to show that there is a protective effect from the use of CFTR modulator therapy and that people with CF from an ethnic minority are at more risk of severe infection with SARS-CoV-2.

Health Care Utilization for Musculoskeletal Issues During the Prediagnosis Period in Psoriatic Arthritis: A Population-Based Study.

OBJECTIVE: Information about the prediagnosis period in psoriatic arthritis (PsA) is limited. The present study was undertaken to compare health care utilization related to musculoskeletal issues during a 5-year period prior to the diagnosis of PsA versus that of subjects with no prior inflammatory arthritis within a primary care setting. METHODS: We conducted a population-based, matched cohort study using electronic medical records and administrative data in Ontario, Canada. Age- and sex-matched cohorts of PsA patients and comparators from the same family physicians were assembled. Comparators were not allowed to have prior spondyloarthritis, ankylosing spondylitis, or rheumatoid arthritis billing code diagnoses. The study outcomes included health care utilization and costs related to nonspecific musculoskeletal issues during a 5-year period prior to the index date. RESULTS: We studied 462 PsA patients and 2,310 matched comparators. The odds ratio (OR) related to visiting a primary care physician for nonspecific musculoskeletal issues in patients with PsA was 2.14 (95% confidence interval 1.73-2.64) in the year immediately preceding the index date and was similarly elevated up to 5 years prior. The OR related to using other musculoskeletal-related health care services, including musculoskeletal specialists visits, joint injections, joint imaging, and emergency department visits, was higher in PsA as early as 5 years preceding the index date. Total and musculoskeletal-related health care costs prior to the index date were higher for patients with PsA versus comparators. CONCLUSION: A prodromal PsA phase characterized by nonspecific musculoskeletal symptoms may exist. Further study is needed to determine if this represents a window for earlier diagnosis of PsA.

Long-term medical imaging use in children with central nervous system tumors.

BACKGROUND: Children with central nervous system (CNS) tumors undergo frequent imaging for diagnosis and follow-up, but few studies have characterized longitudinal imaging patterns. We described medical imaging in children before and after malignant CNS tumor diagnosis. PROCEDURE: We conducted a retrospective cohort study of children aged 0-20 years diagnosed with CNS tumors between 1996-2016 at six U.S. integrated healthcare systems and Ontario, Canada. We collected computed topography (CT), magnetic resonance imaging (MRI), radiography, ultrasound, nuclear medicine examinations from 12 months before through 10 years after CNS diagnosis censoring six months before death or a subsequent cancer diagnosis, disenrollment from the health system, age 21 years, or December 31, 2016. We calculated imaging rates per child per month stratified by modality, country, diagnosis age, calendar year, time since diagnosis, and tumor grade. RESULTS: We observed 1,879 children with median four years follow-up post-diagnosis in the U.S. and seven years in Ontario, Canada. During the diagnosis period (±15 days of diagnosis), children averaged 1.10 CTs (95% confidence interval [CI] 1.09-1.13) and 2.14 MRIs (95%CI 2.12-2.16) in the U.S., and 1.67 CTs (95%CI 1.65-1.68) and 1.86 MRIs (95%CI 1.85-1.88) in Ontario. Within one year after diagnosis, 19% of children had ≥5 CTs and 45% had ≥5 MRIs. By nine years after diagnosis, children averaged one MRI and one radiograph per year with little use of other imaging modalities. CONCLUSIONS: MRI and CT are commonly used for CNS tumor diagnosis, whereas MRI is the primary modality used during surveillance of children with CNS tumors.

Emergency department use in people who experience imprisonment in Ontario, Canada.

OBJECTIVES: The aims of this study were to describe emergency department (ED) utilization by people in provincial prison and on release, and to compare with ED utilization for the general population. METHODS: We linked correctional and health administrative data for people released from provincial prison in Ontario in 2010. We matched each person by age and sex with four people in the general population. We compared ED utilization rates using generalized estimating equations, by sex and for high urgency and ambulatory care sensitive conditions. RESULTS: People who experienced imprisonment (N = 48,861) had higher ED utilization rates compared with the general population (N = 195,444), with rate ratios of 3.2 (95% CI 3.0-4.4) for men and 6.5 (95% CI 5.6-7.5) for women in prison and a range of rate ratios between 3.1 and 7.7 for men and 4.2 and 8.8 for women over the 2 years after release. Most ED visits were high urgency, and between 1.0% and 5.1% of visits were for ambulatory care sensitive conditions. ED utilization rates increased on release from prison. CONCLUSIONS: People experiencing imprisonment in Ontario have higher ED utilization compared with matched people in the general population, primarily for urgent issues, and particularly in women and in the week after release. Providing high-quality ED care and implementing prison- and ED-based interventions could improve health for this population and prevent the need for ED use.

Thirty-day readmission after medical-surgical hospitalization for people who experience imprisonment in Ontario, Canada: A retrospective cohort study.

We aimed to compare 30-day readmission after medical-surgical hospitalization for people who experience imprisonment and matched people in the general population in Ontario, Canada. We used linked population-based correctional and health administrative data. Of people released from Ontario prisons in 2010, we identified those with at least one medical or surgical hospitalization between 2005 and 2015 while they were in prison or within 6 months after release. For those with multiple eligible hospitalizations, we randomly selected one hospitalization. We stratified people by whether they were in prison or recently released from prison at the time of hospital discharge. We matched each person with a person in the general population based on age, sex, hospitalization case mix group, and hospital discharge year. Our primary outcome was 30-day hospital readmission. We included 262 hospitalizations for people in prison and 1,268 hospitalizations for people recently released from prison. Readmission rates were 7.7% (95%CI 4.4-10.9) for people in prison and 6.9% (95%CI 5.5-8.3) for people recently released from prison. Compared with matched people in the general population, the unadjusted HR was 0.72 (95%CI 0.41-1.27) for people in prison and 0.78 (95%CI 0.60-1.02) for people recently released from prison. Adjusted for baseline morbidity and social status, hospitalization characteristics, and post-discharge health care use, the HR for 30-day readmission was 0.74 (95%CI 0.40-1.37) for people in prison and 0.48 (95%CI 0.36-0.63) for people recently released from prison. In conclusion, people recently released from prison had relatively low rates of readmission. Research is needed to elucidate reasons for lower readmission to ensure care quality and access.