Prevalence and management of dyslipidemia in primary care practices in Canada.

OBJECTIVE: To estimate the prevalence of dyslipidemia and to describe its management in Canadian primary care. DESIGN: Retrospective cohort study using primary care electronic medical record data. SETTING: Canada. PARTICIPANTS: Adults aged 40 years or older who saw a Canadian Primary Care Sentinel Surveillance Network contributor between January 1, 2018, and December 31, 2019. MAIN OUTCOME MEASURES: Presence or absence of dyslipidemia as identified by a validated case definition and the treatment status of patients identified as having dyslipidemia based on having been prescribed a lipid-lowering agent (LLA). RESULTS: In total, 50.0% of the 773,081 patients 40 years of age or older who had had a primary care visit in 2018 or 2019 were identified as having dyslipidemia. Dyslipidemia was more prevalent in patients 65 or older (61.5%), in males (56.7%) versus females (44.7%), and in those living in urban areas (50.0%) versus rural areas (45.2%). In patients with documented dyslipidemia, 42.8% had evidence of treatment with an LLA. Stratifying patients by Framingham risk score revealed that those in the high-risk category were more likely to have been prescribed an LLA (65.0%) compared with those in the intermediate-risk group (48.7%) or the low-risk group (22.8%). The strongest determinants of receiving LLA treatment for dyslipidemia include sex, with males being 1.95 times more likely to have been treated compared with females (95% CI 1.91 to 1.98; P<.0001); and body mass index, with those with obesity having a significantly increased likelihood of being treated with an LLA (adjusted odds ratio of 1.36, 95% CI 1.32 to 1.41; P<.0001). CONCLUSION: This study provides an updated look at the prevalence and treatment of dyslipidemia among Canadians. Half of patients aged 40 years or older have dyslipidemia, with an even higher prevalence observed among adults aged 65 years or older, males, and those with obesity or other chronic conditions. There are still gaps in treatment among those with documented dyslipidemia, principally among those calculated to have high or intermediate Framingham risk scores. Particular attention should also be paid to those at higher risk for not receiving treatment, including female patients and those within normal body mass index ranges.

Validation of adult asthma case definitions for primary care sentinel surveillance.

BACKGROUND: Most asthma diagnoses and patient care take place in primary care settings. Electronic medical records (EMRs) offer an opportunity to utilize technology to improve asthma diagnosis and care. The purpose of this study was to create and validate separate case definitions for suspected and confirmed asthma in primary care EMRs, to enable surveillance, benchmarking, and quality improvement in primary care settings. The objective of this study was to develop a case definition for suspected and confirmed asthma for use in a primary care sentinel surveillance system. METHODS: A single chart abstractor conducted a manual audit of 776 randomly selected patient charts from an academic primary care practice EMR in Kingston, Ontario. Following the single chart abstractor classification, a consensus on chart classification as "not asthma", "suspected asthma", or "confirmed asthma" was achieved between the abstractor, a family physician, and a respirologist using Canadian Thoracic Society (CTS) criteria. Case definition algorithms based on billing codes, clinical data elements and medications were applied to the site's Canadian Primary Care Sentinel Surveillance Network (CPCSSN) data for the same charts and compared to abstractor classifications to determine each algorithm's measurement properties. RESULTS: The prevalence of suspected and confirmed asthma were 7.3% (n = 54) and 2.4% (n = 18), respectively. None of the proposed case definitions could differentiate between suspected and confirmed asthma. One algorithm consisting of billing, clinical, and medication elements had the highest Youden's Index for either suspected or confirmed asthma. The algorithm had a sensitivity of 81%, a specificity of 96%, positive predictive value of 71%, negative predictive value of 98%, and a Youden's Index of 0.77 for combined suspected or confirmed asthma cases. CONCLUSION: An EMR case definition for suspected or confirmed adult asthma has been validated for use in CPCSSN. Implementation of this case definition will enable the development of a surveillance electronic tool (eTool) for adult asthma that can foster quality improvement.

Value in Primary Care: Evidence from the Canadian Primary Care Sentinel Surveillance Network.

Primary care antimicrobial stewardship programs are virtually non-existent. Using electronic medical record (EMR) data for an interrupted time series study, the authors examined the relationship between antibiotic prescriptions for acute respiratory tract infections (RTIs) and the COVID-19 pandemic. The main outcome of the study was to gauge the proportion of RTI encounters with an antibiotic prescription. The pre-pandemic RTI antibiotic prescribing rate was 27.8%. During the COVID-19 pandemic, prescribing dropped significantly by 9.4% (p < 0.001). Almost 750,000 fewer patients could potentially avoid receiving an antibiotic prescription for RTI. The authors also discuss the value of EMR data; their use can help develop insights for health system improvement.

Using Administrative Data in Primary Care to Evaluate the Effectiveness of a Continuing Professional Development Program Focused on the Management of Patients Living With Obesity.

INTRODUCTION: There are guidelines for referral to medical and/or surgical weight loss interventions (MSWLI) in Ontario; however, only about one-third of eligible patients in our region are being referred for consideration of MSWLI. METHODS: A planning committee, including a registered dietician, psychiatrist, endocrinologist, bariatric surgeon, family physician, and educationalists, developed an interdisciplinary continuing professional development (CPD) program focused on practical approaches to the management of patients living with obesity. The Kirkpatrick model was used to evaluate the educational outcomes of the CPD program specifically focusing on Level-2, -3, and -4 outcomes based on self-reported questionnaire and health administrative data. RESULTS: Eighteen primary care providers from the CPD program agreed to participate in this study, and 16 primary care providers (89%) completed the postintervention questionnaire and granted us access to their MSWLI referral data; 94% of study participants reported changes to their knowledge, comfort, and confidence (Level 2), as well as expected change in their future behaviour (Level 3) following the CPD program. However, there was no change in Kirkpatrick Level-4 outcomes, despite more than 90% of participants indicating that they will be making changes to their practice after the program. DISCUSSION: The CPD program in our study was overwhelmingly well received and participants reported knowledge (Level 2) and behavioural (Level 3) changes following participation; however, there was no detectable change in their clinical practice (Level 4). The methodology described in our proof-of-concept study can be modified and adopted to evaluate Level-4 outcomes in other studies of effectiveness of CPD interventions.

Baseline Inappropriate Antibiotic Use in Primary Care Patients with Viral Respiratory Tract Infections with 2019 and 2020.

Context: Respiratory tract infection (RTI) is the leading cause of avoidable antimicrobial use in primary care. How the COVID-19 pandemic has impacted antibiotic prescribing practices across Canada is unknown. The purpose of this study was to examine rates of antibiotic prescribing for RTI in primary care during the first year of the pandemic (2020), compared to baseline in 2019. Study Design and Analysis: Cross sectional study. Dataset: Canadian Primary Care Sentinel Surveillance Network electronic medical record data from sites in British Columbia, Alberta, Manitoba, Ontario, Quebec, Nova Scotia and Newfoundland. Population Studied: Patients that met the case definition criteria for an RTI or a Urinary Tract Infection (UTI) in 2019, and in 2020. Outcome measures: We examined oral antibiotic prescribing for patients who were identified as having a primary care visit for RTI. The same analysis was repeated for urinary tract infection (UTI) as a tracer condition. The antibiotic use considered avoidable for RTI was defined by Choosing Wisely Canada. Results: A total of 1,692,876 patients with a valid birth year and sex and at least one visit to primary care in 2019 and 2020 were included. Patient visits for RTI decreased from 2.3% in 2019 to 1.6% in 2020 (p<.0001), as did patient visits for UTI (1.1% vs 0.7%, p<.0001). In 2019, 28.0% of patients visits for RTI were prescribed an antibiotic, and this proportion decreased significantly to 20.6% in 2020 (<.0001). The drop in antibiotic prescriptions for RTI was driven by a decrease in prescribing for common cold (13.6% vs. 11.3%, <.0001) and for acute bronchitis/asthma (15.2% vs. 7.3%, p<.0001). In comparison, antibiotic prescribing for visits related to UTI increased marginally between 2019 and 2020 (71.6% vs. 72.3%, p=0.007). Conclusions: A significant decrease in antibiotic prescribing for RTI across primary care was observed during the first year of the COVID-19 pandemic, likely related to the changes in epidemiology and care delivery models in primary care. CPCSSN can provide pan-Canadian surveillance of antibiotic prescribing practices in primary care that can be used for provider feedback and quality improvement.

Comprehensiveness of care for women with depression: Association between primary care use and cervical cancer screening.

OBJECTIVE: To explore comprehensiveness of care in patients with depression by examining associations between a diagnosis of depression, frequency of primary care visits, and Papanicolaou test completion. DESIGN: Cross-sectional retrospective survey using electronic medical record data from the Canadian Primary Care Sentinel Surveillance Network. SETTING: Primary care practices in Ontario. PARTICIPANTS: Women aged 21 to 69 eligible to receive Pap tests in 2015. MAIN OUTCOME MEASURES: Associations between 2 predictors (depression and number of primary care visits in 2015) and Pap test completion were measured. RESULTS: Overall, 125,258 women were included: 20.5% completed a Pap test and 16.4% had a diagnosis of depression. Having a diagnosis of depression was associated with lower likelihood of Pap test completion (adjusted odds ratio [AOR]=0.92, 95% CI 0.88 to 0.95). A greater number of primary care visits was associated with a higher likelihood of Pap test completion; this association was stronger in women with a diagnosis of depression (AOR=4.9, 95% CI 4.16 to 5.69) than in those without (AOR=3.4, 95% CI 3.25 to 3.60). CONCLUSION: While depression was associated with fewer completed Pap tests, women with depression who saw their family doctors more often were more likely to be screened for cervical cancer. More primary care visits for depression treatment may be associated with an improved likelihood of screening for cervical cancer.

Awareness, management, and practice patterns of pediatric NAFLD by primary care physicians.

Background: Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in children. Primary-care physicians (PCPs) play a key role in identifying patients requiring specialist referral. In this study, we aim to determine PCPs' practice patterns for paediatric NAFLD, as knowledge gaps have been reported for adult NAFLD. Methods: A survey was sent to 60 PCPs in the Eastern Ontario Network from July 2019 to January 2020. Results: Thirty-seven (62%) PCPs responded to the survey. Twenty-one incorrectly considered the prevalence of paediatric NAFLD to be ≤10%. The majority (35/36) cared for less than five paediatric NAFLD patients. Thirty-four (92%) were only 'slightly familiar' or 'not familiar at all' with paediatric NAFLD. Only one PCP routinely screens for NAFLD. Only one PCP was aware of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) clinical guidelines for paediatric NAFLD. Twenty-five (68%) correctly selected lifestyle modifications as a treatment option. Lack of confidence in the knowledge of NAFLD was the most common barrier for managing paediatric cases. Conclusion: The majority of PCPs are not screening for paediatric NAFLD and are not familiar with its clinical spectrum, citing a lack of knowledge regarding NAFLD as the greatest barrier. This may cause delays in diagnosis and a presentation with advanced fibrosis at the time of specialist referral. Dissemination and implementation of clinical guidelines have the potential to improve knowledge and screening rates for NAFLD in children at the primary-care level.

Antibiotic prescribing for respiratory tract infection across a national primary care network in 2019.

Background: Respiratory tract infection (RTI) is the leading reason for avoidable antimicrobial use in primary care, yet provider-level feedback on its use is only available in some provinces. The aim of this study was to validate case definitions for RTI across the Canadian Primary Care Sentinel Surveillance Network (CPCSSN) and determine baseline provider-level variability in antimicrobial prescribing in 2019. Methods: The RTI case definitions were developed using demographic, diagnostic coding and keywords in electronic medical record. Manual chart abstraction was performed to identify cases of acute otitis media. Remaining RTI definitions were validated using a random sample of 5,164 patients with encounters in 2019. The proportion of patients with an RTI treated with antibiotics was determined by provider, per patient, per episode and per patient encounter. Results: Negative predictive value, positive predictive value and prevalence were as follows: 1.00 (0.99-1.00), 0.99 (0.96-0.99) and 4.14% (4.10-4.19) for common cold; 1.00 (0.99-1.00), 0.94 (0.88-0.98) and 1.09% (1.07-1.12) for acute otitis media; 0.98 (0.96-1.00), 0.93 (0.87-0.97) and 1.2% (1.18-1.22) for acute pharyngitis; 0.99 (0.99-1.00), 0.88 (0.81-0.93) and 1.99% (1.96-2.02) for sinusitis; 0.99 (0.97-0.99), 0.95 (0.89-0.98) and 4.01% (3.97-4.05) for acute bronchitis/asthma. By provider, median (interquartile range [IQR]) proportion treated with antibiotics (per patient) was 6.72 (14.92) for common cold, 64.29 (40.00) for acute otitis media, 20.00 (38.89) for pharyngitis, 54.17 (38.09) for sinusitis, 8.33 (20.00) for acute bronchitis/asthma and 21.10 (20.56) for overall RTI. Conclusion: The CPCSSN can provide national surveillance of antimicrobial prescribing practices for RTI across primary care. Baseline variability underscores the need for provider feedback and quality improvement.

Screening patterns and identification of non-alcoholic fatty liver disease in obese children in canadian primary care.

Context. Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in children. There is no epidemiological data on rates of pediatric NAFLD in Canada. Primary care physicians (PCPs) are often the first contact healthcare professionals to manage potential pediatric patients with NAFLD. Objective: Evaluate patterns of screening and identification of pediatric NAFLD in Canadian primary care using administrative health care database. Study Design: Cross-sectional observational study. Dataset: The Canadian Primary Care Sentinel Surveillance Network (CPCSSN), a repository of clinical electronic medical record data drawn from primary care practices across Canada. Population Studied: Children aged 9-18 years old between July 1, 2018 and December 31, 2019. Outcome Measures: The proportion of children eligible for screening (BMI≥95th percentile) as per NASPGHAN guidelines using ALT levels. Logistic Regression was used to evaluate the predictors for screening. Suspected NAFLD was defined as elevated ALT (>22 U/L for girls and > 26 U/L for boys) in the absence of viral hepatitis, metabolic conditions, alcohol use, hepatotoxic medications. Results: The study sample consisted of 66,872 children, of which 15.8% (n=10,539) had a BMI≥95th percentile and only 10.1% (n=1,067/10539) were screened in the last year using ALT. Children were more likely to get screened if they were a) older (13-18 year vs 9-12 year, OR=1.63, 95% CI 1.38-1.93); b) living in an urban setting (OR=1.34, 95% CI 1.0-1.63); and c) had a higher BMI (≥99th percentile vs 95th-98th, OR=1.34, 95% CI 1.14, 1.56). We identified 855 cases of suspected NAFLD, most children (78.5%) were older (13-18 years), male (55.0%), and lived in an urban setting (71.5%). A significant proportion (40.4%) had a BMI in the 99th percentile and 60.3% had at least one comorbidity, and 35.9% were prescribed a psychotropic, antidiabetic or antihypertensive medications. Only 19.9% were referred to a specialist (pediatrician, gastroenterologist). Conclusions: This is the first study to estimate the screening patterns of pediatric NAFLD in primary care in Canada at a national level. The study revealed low screening rates in primary care, these results will help facilitate prioritization of care and future work that could evaluate successful implementation strategies while emphasizing the role of PCPs in screening and managing pediatric NAFLD in Canadian health care setting.

Screening Patterns of Nonalcoholic Fatty Liver Disease in Children with Obesity in Canadian Primary Care: A Cross-Sectional Study.

Background: Nonalcoholic fatty liver disease (NAFLD) is the most common pediatric chronic liver disease, and children with a body mass index (BMI) ≥95th percentile are recommended to be screened for NAFLD by liver enzymes. Objectives: This study aimed to determine the frequency and predictors of screening for NAFLD among children with obesity in Canada and to evaluate a sample of children with suspected NAFLD. Methods: This cross-sectional study used data from the Canadian Primary Care Sentinel Surveillance Network, a repository of electronic medical record data from Canadian primary care practices. Results: Of n = 110,827 children aged 9-18 years, 13.9% (n = 9,888) had a BMI ≥95th percentile. Only 8.7% (n = 859) of these patients were screened for NAFLD in the last year, and 23.6% (n = 2336) were ever screened. Using logistic regression, screening in the last year was associated with demographic and clinical characteristics, including previous liver enzyme assessment, prior antidiabetic prescription, and prior anxiolytic prescription. Among children with suspected NAFLD (n = 1,046), 34.7% had a BMI ≥99th percentile and approximately 8% were at increased risk of significant liver disease. Conclusion: The study revealed low screening rates for NAFLD in Canadian primary care and highlighted the important role of primary care providers in identifying and managing pediatric NAFLD.

Patients eligible and referred for bariatric surgery in southeastern Ontario: Retrospective cohort study.

OBJECTIVE: To evaluate the proportion of eligible individuals, within one health region in Ontario, who were referred for publicly funded medical and surgical weight-loss interventions (MSWLI). DESIGN: A retrospective cohort study that used primary care data from the Canadian Primary Care Sentinel Surveillance Network (CPCSSN) and referral data from the Ontario Bariatric Network (OBN). SETTING: Primary care practices within southeastern Ontario that contribute data to CPCSSN. PARTICIPANTS: Patients with class II (body mass index [BMI] 35.0 to 39.9 kg/m2) or III (BMI ≥ 40 kg/m2) obesity who were eligible for referral to the OBN for MSWLI. MAIN OUTCOME MEASURES: Primary care data about patients within the CPCSSN database were linked to referral records within the OBN database using 3 indirect identifiers to determine the proportion of patients with class II and III obesity who were referred to the OBN for MSWLI. An adjusted multivariate logistic regression model was used to determine the most significant predictors of referral. RESULTS: Of the 87 276 patients within one health region in Ontario, 15 526 (17.8%) patients had class II or III obesity and were eligible for referral for MSWLI. Only 966 out of those 15 526 (6.2%) patients were actually referred for MSWLI. In the multivariate regression analysis, BMI had the strongest association with referral in terms of adjusted odds ratio (AOR), varying from 2.50 (95% CI 2.04 to 3.06) for a BMI of 40.0 to 44.9 kg/m2, to 5.15 (95% CI 4.21 to 6.30) for a BMI of 50.0 kg/m2 or greater. Referral was more likely for female than male patients (AOR = 2.18; 95% CI 1.86 to 2.57), those living rurally than for urban dwellers (AOR = 1.39; 95% CI 1.20 to 1.60), and those aged 30 to 39 (AOR = 1.61; 95% CI 1.24 to 2.09) and 40 to 49 (AOR = 1.53; 95% CI 1.18 to 1.98) compared with other age groups. CONCLUSION: Within one health region in Ontario, the referral rate of patients with class II and III obesity for MSWLI was low. Our findings highlight the need for further research to understand and address the barriers to referral of patients with class II and III obesity for MSWLI.

Validation of an EMR algorithm to measure the prevalence of ADHD in the Canadian Primary Care Sentinel Surveillance Network (CPCSSN).

BACKGROUND: Building and validating electronic algorithms to identify patients with specific disease profiles using health data is becoming increasingly important to disease surveillance and population health management. The aim of this study was to develop and validate an algorithm to find patients with ADHD diagnoses within primary care electronic medical records (EMR); and then use the algorithm to describe the epidemiology of ADHD from 2008 to 2015 in a Canadian Primary care sample. METHODS: This was a cross sectional time series that used data from the Canadian Primary Care Sentinel Surveillance Network (CPCSSN), a repository of primary care EMR data. A sample of electronic patient charts from one local clinic were manually reviewed to determine the positive predictive value (PPV) and negative predictive value (NPV) of an ADHD case-finding algorithm. In each study year a practice population was determined, and the algorithm was used to measure an observed prevalence of ADHD. The observed prevalence was adjusted for misclassification, as measured by the validity indices, to obtain an estimate of the true prevalence. Estimates were calculated by age group (4-17 year olds, 18 to 34 year olds, and 35 to 64 year olds) and gender, and compared over time. RESULTS: The EMR algorithm had a PPV of 98.0% (95% CI [92.5, 99.5]) and an NPV of 95.0% (95% CI [92.9, 98.6]). After adjusting for misclassification, it was determined that the prevalence of patients with a clinical diagnosis of ADHD has risen in all age groups between 2008 and 2015, most notably in children and young adults (6.92, 95% CI [5.62, 8.39] to 8.57, 95% CI [7.32, 10.00]; 5.73, 95% CI [4.40, 7.23] to 7.33, 95% CI [6.04, 8.78], respectively). The well-established gender gap persisted in all age groups across time but was considerably smaller in older adults compared to children and young adults. CONCLUSION: Overall, the ADHD case-finding algorithm was found to be a valid tool to assess the epidemiology of ADHD in Canadian primary care practice. The increased prevalence of ADHD between 2008 and 2015 may reflect an improvement in the recognition and treatment of this disorder within primary care.

Recent Trends in the Prescribing of ADHD Medications in Canadian Primary Care.

Objective: The aim of this study was to describe the prevalence and incidence of ADHD medication prescribing, by age and gender, from 2005 to 2015 in Canadian primary care. Method: A population-based retrospective cohort study was conducted to evaluate the prescribing of ADHD medications between 2005 and 2015 using electronic medical record data. Yearly prevalence and incidence of ADHD medication prescribing were calculated for preschoolers (up to 5 years old), school-aged children (6-17 years old), and adults (18-65 years old) along with a description of the types of ADHD medications prescribed between 2005 and 2015. Results: Between 2005 and 2015, there was a 2.6-fold increase in the prevalence of ADHD medication prescribing to preschoolers, a 2.5-fold increase in school-aged children, and a fourfold increase in adults. There was a corresponding rise in incidence of prescribing although this rise was moderate and estimates were much lower compared with prevalence. The most commonly prescribed medication was Methylphenidate (65.0% of all ADHD medications prescribed). Conclusion: Although the prevalence of ADHD has remained stable over time, this study found an increase in the prescribing of ADHD medications in all age groups between 2005 and 2015. Incidence of new prescriptions was small relative to prevalence, suggesting that longer term treatments are being adopted.

Barriers to accessing weight-loss interventions for patients with class II or III obesity in primary care: a qualitative study.

BACKGROUND: Over 1 million Canadians have class II or III obesity; however, access to weight-loss interventions for these patients remains limited. The purpose of our study was to identify the barriers to accessing medical and surgical weight-loss interventions from the perspectives of 3 groups: family physicians, patients who were referred for weight-loss intervention and patients who were not referred for weight-loss intervention. METHODS: Between November 2017 and May 2018, we conducted a qualitative exploratory research study using focus groups with family physicians and interviews with patients with class II or III obesity from 1 region in southern Ontario. We conducted a thematic analysis to identify emergent themes and used the barriers to change theory to classify the similarities and differences between the perspectives of family physicians, referred patients and nonreferred patients in first- and second-order barriers. RESULTS: Seventeen family physicians participated in 7 focus groups (1-4 participants/group), and we interviewed 8 referred patients and 7 nonreferred patients. We identified lack of resource supports, logistics and lack of knowledge about weight-loss interventions as first-order barriers to change, and lack of knowledge about root causes of obesity, lack of patient readiness for change and family physicians' perceptions about surgical weight loss as second-order barriers to change. Family physicians and patients had similar perceptions regarding lack of resource supports in the community, logistical issues, family physicians' lack of knowledge regarding weight-loss interventions, patients' lack of motivation and family physicians' perceptions of bariatric surgery as being high risk. They differed regarding the root cause of obesity, with family physicians attributing obesity to multiple extrinsic and intrinsic causes, whereas patients believed obesity was largely due to intrinsic causes alone. INTERPRETATION: It is important to address first- and second-order barriers to accessing weight-loss interventions through continuing professional development activities for family physicians to help ensure effective and timely treatment for patients with class II or III obesity and related comorbidities.

Trends in antidepressant prescribing to children and adolescents in Canadian primary care: A time-series analysis.

PURPOSE: The purpose of this study was to describe the trends and patterns of antidepressant (AD) prescribing to children and adolescents in Canadian primary care before and after the black-box warning in 2004. METHODS: Prescription data from the Canadian Primary Care Sentinel Surveillance Network, a repository of primary care data on over 1 million patients, was used to analyze AD prescribing to children (8-11 y) and adolescents (12-18 y) between 2000 and 2014. Interrupted time series analyses were used to assess the impact of the 2004 black-box warning on the prescribing levels of ADs. RESULTS: The 2004 black-box warning had a significant and immediate effect on the prescribing of AD. However, this drop was not sustained, and 5 years after the advisory AD prescribing rates reversed direction and started to rise. Selective serotonin reuptake inhibitors dominated as the most common AD prescribed throughout the study period, increasing from 66% prior to the black-box warning to 83.12% after 2009. CONCLUSIONS: The black-box warning effectively reduced AD prescribing in primary care for approximately 5 years before a reversal back to a positive rate of prescribing. This rebounding could reflect an emerging consensus about the trade-off in risks and benefits.

Prevalence of toddler, child and adolescent overweight and obesity derived from primary care electronic medical records: an observational study.

BACKGROUND: Population monitoring and surveillance of objectively measured child weight data in Canada is limited to national surveys with poor regional applicability, and no healthy weight data are available for children less than 2 years of age. We aimed to determine the prevalence of childhood overweight and obesity using objective measures derived from primary care electronic medical records. METHODS: Observational data included all height and weight records for children less than 20 years of age, between 2004 and 2013, from 3 Ontario primary care research networks. We calculated body mass index (BMI)-for-age and weight-for-length using the World Health Organization Growth Standards and Reference to assign growth status indicator categories by age group. Descriptive data and prevalence estimates were generated for 2013. We also compared weight-for-length for children less than 2 years of age with a corresponding billing code for known well-child visits. RESULTS: Our study included 8261 children with a corresponding growth status indicator, a sample close to 4 times larger than the national survey sample. In 2013, 28.4% of children aged 5-19 years, and 6% of children aged 0-5 years, were categorized as overweight or obese. Between 2008 and 2013, the total number of 18-month well baby visit billing codes was 1152; 6.9% of this group were categorized as overweight or obese; 19.2% were categorized as having risk of overweight. INTERPRETATION: Primary care electronic medical records show good potential for ongoing population monitoring of overweight and obesity, particularly for very young children for whom early intervention is likely to show the greatest positive health impact.

Representativeness of patients and providers in the Canadian Primary Care Sentinel Surveillance Network: a cross-sectional study.

BACKGROUND: The Canadian Primary Care Sentinel Surveillance Network (CPCSSN) has established a national repository of primary care patient health data that is used for both surveillance and research. Our main objective was to determine how representative the data for patients and primary care practitioners in the CPCSSN are when compared with the Canadian population. METHODS: In this cross-sectional study, we compared the 2013 CPCSSN patient sample with age and sex information from the 2011 census. The CPCSSN provider sample in 2013 was compared with the 2013 National Physician Survey. Results were stratified by 5 clinically relevant age categories and sex, and male-to-female ratios were calculated. RESULTS: Patients who were 65 years of age and older represented 20.4% of the CPCSSN sample but only represented 14.8% of the Canadian population (2011 census). Among young adults (20-39 yr), 39.3% fewer men than women visited their primary care practitioner within 2 years. CPCSSN sample practitioners were more likely to be under 45 years of age, more likely to be female and more likely to be in an academic practice. INTERPRETATION: It is important to consider adjusting for age and sex when using CPCSSN data. CPCSSN practitioners are likely not representative of family physicians; therefore, CPCSSN needs to recruit more nonacademic practices, community clinics and practices that have a larger proportion of male providers.

Utility of linking primary care electronic medical records with Canadian census data to study the determinants of chronic disease: an example based on socioeconomic status and obesity.

BACKGROUND: Electronic medical records (EMRs) used in primary care contain a breadth of data that can be used in public health research. Patient data from EMRs could be linked with other data sources, such as a postal code linkage with Census data, to obtain additional information on environmental determinants of health. While promising, successful linkages between primary care EMRs with geographic measures is limited due to ethics review board concerns. This study tested the feasibility of extracting full postal code from primary care EMRs and linking this with area-level measures of the environment to demonstrate how such a linkage could be used to examine the determinants of disease. The association between obesity and area-level deprivation was used as an example to illustrate inequalities of obesity in adults. METHODS: The analysis included EMRs of 7153 patients aged 20 years and older who visited a single, primary care site in 2011. Extracted patient information included demographics (date of birth, sex, postal code) and weight status (height, weight). Information extraction and management procedures were designed to mitigate the risk of individual re-identification when extracting full postal code from source EMRs. Based on patients' postal codes, area-based deprivation indexes were created using the smallest area unit used in Canadian censuses. Descriptive statistics and socioeconomic disparity summary measures of linked census and adult patients were calculated. RESULTS: The data extraction of full postal code met technological requirements for rendering health information extracted from local EMRs into anonymized data. The prevalence of obesity was 31.6 %. There was variation of obesity between deprivation quintiles; adults in the most deprived areas were 35 % more likely to be obese compared with adults in the least deprived areas (Chi-Square = 20.24(1), p < 0.0001). Maps depicting spatial representation of regional deprivation and obesity were created to highlight high risk areas. CONCLUSIONS: An area based socio-economic measure was linked with EMR-derived objective measures of height and weight to show a positive association between area-level deprivation and obesity. The linked dataset demonstrates a promising model for assessing health disparities and ecological factors associated with the development of chronic diseases with far reaching implications for informing public health and primary health care interventions and services.

Adult obesity prevalence in primary care users: An exploration using Canadian Primary Care Sentinel Surveillance Network (CPCSSN) data.

OBJECTIVES: This research examines the feasibility of using electronic medical records within the Canadian Primary Care Sentinel Surveillance Network (CPCSSN) for obesity surveillance in Canada by assessing obesity trends over time and comparing BMI distribution estimates from CPCSSN to those obtained from nationally representative surveys. METHODS: Data from 2003-2012 on patients 18 years and older (n = 216,075) were extracted from the CPCSSN database. Patient information included demographics (age and sex) and anthropometric measures (height, weight, body mass index (BMI), waist circumference, and waist-to-hip ratio). Standard descriptive statistics were used to characterize the sample, including, as appropriate, means, proportions and medians. The BMI distribution of the CPCSSN population was compared to estimates from the Canadian Community Health Survey (CCHS) and the Canadian Health Measures Survey (CHMS) for the years: 2004, 2007-2009 and 2009-2011. RESULTS: The estimated prevalence of obesity increased from 17.9% in 2003 to 30.8% in 2012. Obesity class I, II and III prevalence estimates from CPCSSN in 2009-2011 (18.0%, 95% CI: 17.8-18; 7.4%, 95% CI: 7.3-7.6; 4.2%, 95% CI: 4.1-4.3 respectively) were greater than those from the most recent (2009- 2011) cycle of the CHMS (16.2%, 95% CI: 14-18.7; 6.3%, 95% CI: 4.6-8.5; 3.7%, 95% CI: 2.8-4.8 respectively), however these differences were not statistically significant. CONCLUSION: The data from CPCSSN present a unique opportunity for longitudinal obesity surveillance among primary care users in Canada, and offer prevalence estimates similar to those obtained from nationally representative survey data.