Contribution of prepregnancy body mass index and gestational weight gain to adverse neonatal outcomes: population attributable fractions for Canada.

BACKGROUND: Low or high prepregnancy body mass index (BMI) and inadequate or excess gestational weight gain (GWG) are associated with adverse neonatal outcomes. This study estimates the contribution of these risk factors to preterm births (PTBs), small-for-gestational age (SGA) and large-for-gestational age (LGA) births in Canada compared to the contribution of prenatal smoking, a recognized perinatal risk factor. METHODS: We analyzed data from the Canadian Maternity Experiences Survey. A sample of 5,930 women who had a singleton live birth in 2005-2006 was weighted to a nationally representative population of 71,200 women. From adjusted odds ratios, we calculated population attributable fractions to estimate the contribution of BMI, GWG and prenatal smoking to PTB, SGA and LGA infants overall and across four obstetric groups. RESULTS: Overall, 6% of women were underweight (<18.5 kg/m(2)) and 34.4% were overweight or obese (≥25.0 kg/m(2)). More than half (59.4%) gained above the recommended weight for their BMI, 18.6% gained less than the recommended weight and 10.4% smoked prenatally. Excess GWG contributed more to adverse outcomes than BMI, contributing to 18.2% of PTB and 15.9% of LGA. Although the distribution of BMI and GWG was similar across obstetric groups, their impact was greater among primigravid women and multigravid women without a previous PTB or pregnancy loss. The contributions of BMI and GWG to PTB and SGA exceeded that of prenatal smoking. CONCLUSIONS: Maternal weight, and GWG in particular, contributes significantly to the occurrence of adverse neonatal outcomes in Canada. Indeed, this contribution exceeds that of prenatal smoking for PTB and SGA, highlighting its public health importance.

Contribution of prepregnancy body mass index and gestational weight gain to caesarean birth in Canada.

BACKGROUND: Overweight and obese women are known to be at increased risk of caesarean birth. This study estimates the contribution of prepregnancy body mass index (BMI) and gestational weight gain (GWG) to caesarean births in Canada. METHODS: We analyzed data from women in the Canadian Maternity Experiences Survey who had a singleton term live birth in 2005-2006. Adjusted odds ratios for caesarean birth across BMI and GWG groups were derived, separately for nulliparous women and parous women with and without a prior caesarean. Population attributable fractions of caesarean births associated with above normal BMI and excess GWG were calculated. RESULTS: The overall caesarean birth rate was 25.7%. Among nulliparous and parous women without a previous caesarean birth, rates in obese women were 45.1% and 9.7% respectively, and rates in women who gained above their recommended GWG were 33.5% and 8.0% respectively. Caesarean birth was more strongly associated with BMI than with GWG. However, due to the high prevalence of excess GWG (48.8%), the proportion of caesareans associated with above normal BMI and excess GWG was similar [10.1% (95% CI: 9.9-10.2) and 10.9% (95% CI: 10.7-11.1) respectively]. Overall, one in five (20.2%, 95% CI: 20.0-20.4) caesarean births was associated with above normal BMI or excess GWG. CONCLUSIONS: Overweight and obese BMI and above recommended GWG are significantly associated with caesarean birth in singleton term pregnancies in Canada. Strategies to reduce caesarean births must include measures to prevent overweight and obese BMI prior to conception and promote recommended weight gain throughout pregnancy.

Temporal trends in postpartum hemorrhage and severe postpartum hemorrhage in Canada from 2003 to 2010.

OBJECTIVE: Increases in postpartum hemorrhage have been reported from several countries. We assessed temporal trends in postpartum hemorrhage and severe postpartum hemorrhage in Canada between 2003 and 2010. METHODS: We carried out a population-based cohort study of all hospital deliveries in Canada (excluding Quebec) from 2003 to 2010 (n = 2 193 425), using data from the Canadian Institute for Health Information. Postpartum hemorrhage was defined as a blood loss of ≥ 500 mL following vaginal delivery or ≥ 1000 mL following Caesarean section, or as noted by the care provider. Severe postpartum hemorrhage was defined as postpartum hemorrhage plus blood transfusion, hysterectomy, or other procedures to control bleeding (including uterine suturing or ligation/embolization of pelvic arteries). Temporal trends were assessed using the chi-square test for trend, relative risks, and logistic regression. RESULTS: Postpartum hemorrhage increased by 22% (95% CI 20% to 25%) from 5.1% in 2003 to 6.2% in 2010 (P < 0.001), driven by a 29% increase (95% CI 26% to 33%) in atonic postpartum hemorrhage (3.9% in 2003 vs. 5.0% in 2010, P < 0.001). Postpartum hemorrhage with blood transfusion increased from 36.7 to 50.4 per 10 000 deliveries (P < 0.001), while postpartum hemorrhage with hysterectomy increased from 4.9 to 5.8 per 10 000 deliveries (P < 0.01). Postpartum hemorrhage with uterine suturing, or ligation/embolization of pelvic arteries, increased from 4.1 to 10.7 per 10 000 deliveries (P < 0.001). These increases occurred in most provinces and territories, and could not be explained by changes in maternal, fetal, and obstetric factors. CONCLUSION: Rates of postpartum hemorrhage and severe postpartum hemorrhage continued to increase in Canada between 2003 and 2010.

Objectif : Une hausse des taux d'hémorragie postpartum a été signalée dans plusieurs pays. Nous avons évalué les tendances temporelles en matière d'hémorragie postpartum et d'hémorragie postpartum grave au Canada pour la période se situant entre 2003 et 2010. Méthodes : Nous avons mené une étude de cohorte en population générale ayant porté sur tous les accouchements hospitaliers au Canada (exception faite du Québec) pour la période se situant entre 2003 et 2010 (n = 2 193 425), au moyen des données issues de l'Institut canadien d'information sur la santé. L'hémorragie postpartum a été définie comme étant une perte sanguine ≥ 500 ml à la suite d'un accouchement vaginal ou ≥ 1 000 ml à la suite d'une césarienne, ou encore conformément aux notes du fournisseur de soins. L'hémorragie postpartum grave a été définie comme étant une hémorragie postpartum s'accompagnant d'une transfusion sanguine, d'une hystérectomie ou d'autres interventions visant à juguler les saignements (y compris les sutures utérines ou la ligature / l'embolisation des artères pelviennes). Les tendances temporelles ont été évaluées au moyen d'un test du chi carré (pour ce qui est de l'évolution), des risques relatifs et d'une régression logistique. Résultats : Le taux d'hémorragie postpartum a connu une hausse de 22 % (IC à 95 %, 20 % - 25 %), soit de 5,1 % en 2003 à 6,2 % en 2010 (P < 0,001), déterminée par une hausse de 29 % (IC à 95 %, 26 % - 33 %) du taux d'hémorragie postpartum par atonie utérine (3,9 % en 2003 vs 5,0 % en 2010, P < 0,001). Le taux d'hémorragie postpartum s'accompagnant d'une transfusion sanguine est passé de 36,7 à 50,4 par 10 000 accouchements (P < 0,001), tandis que le taux d'hémorragie postpartum s'accompagnant d'une hystérectomie est passé de 4,9 à 5,8 par 10 000 accouchements (P < 0,01). Le taux d'hémorragie postpartum s'accompagnant de sutures utérines ou d'une ligature / embolisation des artères pelviennes est passé de 4,1 à 10,7 par 10 000 accouchements (P < 0,001). Ces hausses se sont manifestées dans la plupart des provinces et des territoires, et ne pouvaient être expliquées par des modifications affectant des facteurs maternels, fœtaux ou obstétricaux. Conclusion : Les taux d'hémorragie postpartum et d'hémorragie postpartum grave ont poursuivi leur croissance au Canada entre 2003 et 2010.

Temporal trends in social disparities in maternal smoking and breastfeeding in Canada, 1992-2008.

A steady decrease in maternal smoking during pregnancy and a steady increase in breastfeeding rates have been observed in Canada in the past two decades. However, the extent to which all socioeconomic classes have benefited from this progress is unknown. Therefore, this study was undertaken to determine: (1) whether progress achieved benefited the entire population or was limited to specific strata; and (2) whether disparities among strata decreased, stayed the same, or increased over time. We used data from the National Longitudinal Survey of Children and Youth, which enrolled children aged 0-3 years between 1994 and 2008. Data collected at entry was analyzed in a cross-sectional manner. Between birth years 1992-1996 and 2005-2008, smoking during pregnancy decreased from 11.5 % (95 % CI 10.0-13.0 %) to 5.2 % (95 % CI 4.1-6.3 %) among mothers with a college or university degree and from 43.0 % (95 % CI 38.8-47.2 %) to 38.6 % (95 % CI 32.9-44.2 %) among those with less than secondary education. During the same period, the rate of breastfeeding initiation increased from 83.8 % (95 % CI 81.9-85.6 %) to 91.5 % (95 % CI 90.2-92.8 %) among mothers with a college or university degree and from 63.1 % (95 % CI 58.9-67.4 %) to 74.7 % (95 % CI 69.8-79.7 %) among those with less than secondary education. The risks of smoking and of not breastfeeding remained significantly higher in the least educated category than in the most educated throughout the study period, and these associations remained statistically significant after controlling for maternal age. Gaps between the least and the most educated mothers narrowed for breastfeeding but widened for smoking during pregnancy.

Gestational age-specific severe maternal morbidity associated with labor induction.

OBJECTIVE: The purpose of this study was to examine the association between labor induction and gestational age-specific severe maternal morbidity. STUDY DESIGN: Our study was restricted to women who delivered singletons at 37-42 weeks' gestation who had no pregnancy complications from 2003-2010 (n = 1,601,253) in Canada (excluding Quebec). Using a pregnancies-at-risk approach, the week-specific rates of specific morbidity after induction were contrasted with rates among ongoing pregnancies. Logistic regression was used to adjust for confounders. RESULTS: Induction increased the rate of postpartum hemorrhage that required blood transfusion at 38 weeks' gestation (adjusted rate ratio, 1.28; 95% confidence interval, 1.11-1.49) and 39 weeks' gestation (adjusted rate ratio, 1.21; 95% confidence interval, 1.06-1.38). Induction was also associated with higher rates of pueperal sepsis at 38 and 39 weeks' gestation and venous thromboembolism at 38 weeks' gestation. The absolute increase in morbidity rates was small; the number needed to harm was large (eg, 1270 for postpartum hemorrhage with blood transfusion at 38 weeks' gestation). CONCLUSION: Among women without pregnancy complications, induction at earlier term is associated with higher rates of specific severe maternal morbidity, although absolute risks are low.

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.

Estimating the completeness of physician billing claims for diabetes case ascertainment: a multiprovince investigation. / Estimation de l'exhaustivité des demandes de remboursement des médecins dans une optique de détermination des cas de diabète : étude menée dans plusieurs provinces.

INTRODUCTION: Previous research has suggested that how physicians are paid may affect the completeness of billing claims for estimating chronic disease. The purpose of this study is to estimate the completeness of physician billings for diabetes case ascertainment. METHODS: We used administrative data from eight Canadian provinces covering the period 1 April 2014 to 31 March 2016. The patient cohort was stratified into two mutually exclusive groups based on their physician remuneration type: fee-for-service (FFS), for those paid only on that basis; and non-fee-for-service (NFFS). Using diabetes prescription drug data as our reference data source, we evaluated whether completeness of disease case ascertainment varied with payment type. Diabetes incidence rates were then adjusted for completeness of ascertainment. RESULTS: The cohort comprised 86 110 patients. Overall, equal proportions received their diabetes medications from FFS and NFFS physicians. Overall, physician payment method had little impact upon the percentage of missed diabetes cases (FFS, 14.8%; NFFS, 12.2%). However, the difference in missed cases between FFS and NFFS varied widely by province, ranging from -1.0% in Nova Scotia to 29.9% in Newfoundland and Labrador. The difference between the observed and adjusted disease incidence rates also varied by province, ranging from 22% in Prince Edward Island to 4% in Nova Scotia. CONCLUSION: The difference in the loss of cases by physician remuneration method varied across jurisdictions. This loss may contribute to an underestimation of disease incidence. The method we used could be applied to other chronic diseases for which drug therapy could serve as reference data source.

Global Epidemiology of Hip Fractures: Secular Trends in Incidence Rate, Post-Fracture Treatment, and All-Cause Mortality.

In this international study, we examined the incidence of hip fractures, postfracture treatment, and all-cause mortality following hip fractures, based on demographics, geography, and calendar year. We used patient-level healthcare data from 19 countries and regions to identify patients aged 50 years and older hospitalized with a hip fracture from 2005 to 2018. The age- and sex-standardized incidence rates of hip fractures, post-hip fracture treatment (defined as the proportion of patients receiving anti-osteoporosis medication with various mechanisms of action [bisphosphonates, denosumab, raloxifene, strontium ranelate, or teriparatide] following a hip fracture), and the all-cause mortality rates after hip fractures were estimated using a standardized protocol and common data model. The number of hip fractures in 2050 was projected based on trends in the incidence and estimated future population demographics. In total, 4,115,046 hip fractures were identified from 20 databases. The reported age- and sex-standardized incidence rates of hip fractures ranged from 95.1 (95% confidence interval [CI] 94.8-95.4) in Brazil to 315.9 (95% CI 314.0-317.7) in Denmark per 100,000 population. Incidence rates decreased over the study period in most countries; however, the estimated total annual number of hip fractures nearly doubled from 2018 to 2050. Within 1 year following a hip fracture, post-hip fracture treatment ranged from 11.5% (95% CI 11.1% to 11.9%) in Germany to 50.3% (95% CI 50.0% to 50.7%) in the United Kingdom, and all-cause mortality rates ranged from 14.4% (95% CI 14.0% to 14.8%) in Singapore to 28.3% (95% CI 28.0% to 28.6%) in the United Kingdom. Males had lower use of anti-osteoporosis medication than females, higher rates of all-cause mortality, and a larger increase in the projected number of hip fractures by 2050. Substantial variations exist in the global epidemiology of hip fractures and postfracture outcomes. Our findings inform possible actions to reduce the projected public health burden of osteoporotic fractures among the aging population. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Breastfeeding policies and practices in Canadian hospitals: comparing 1993 with 2007.

BACKGROUND: The Baby-Friendly Hospital Initiative (BFHI) promotes the World Health Organization International Code of Marketing of Breast-milk Substitutes (WHO Code) and the WHO/UNICEF's Ten Steps to Successful Breastfeeding (Ten Steps). The purpose of this study is to describe and compare maternity hospitals' adherence to the BFHI in 1993 and 2007 for Canada and for each province and territory. METHODS: A survey of all Canadian maternity hospitals was conducted in 1993 and 2007 on routine maternity care practices and policies including infant feeding. RESULTS: The overall response rate was 91 percent (n = 523/572 hospitals) in 1993 and 92 percent (n = 323/353 hospitals) in 2007. Eighty-two percent (415/507) of hospitals in 1993 and 68 percent (198/292) in 2007 had exclusive contracts with formula companies. Fifty-eight percent (302/517) of hospitals in 1993 and 90 percent (289/322) in 2007 never gave breastfeeding mothers sample packs containing formula. Fifty-eight percent (296/507) in 1993 and 85 percent (273/321) in 2007 had written breastfeeding policies (Step 1); 97 percent (503/518) in 1993 and 99 percent (320/322) in 2007 allowed mothers to breastfeed, on cue, whenever the babies indicated an interest 24 hours a day (Step 8); 24 percent (126/519) in 1993 and 64 percent (206/321) in 2007 reported that they did not provide soothers (Step 9); 58 percent (297/513) in 1993 and 68 percent (215/316) in 2007 always offered information on breastfeeding support groups and/or advice at time of discharge (Step 10). CONCLUSIONS: In the 14 years separating the two surveys, Canadian maternity hospitals substantially improved their implementation of the WHO Code and their adherence to the WHO/UNICEF Ten Steps.

Temporal trends in maternal mortality in Canada I: estimates based on vital statistics data.

OBJECTIVES: Vital Statistics and World Health Organization reports show a recent increase in maternal mortality in Canada. We carried out a study of temporal trends, regional variations, and causes of death in Canadian maternal mortality using Vital Statistics data. METHODS: We used Vital Statistics death registrations to ascertain maternal deaths between 1981 and 2007. Maternal mortality rates, risk ratios, and 95% confidence intervals were estimated, and the Cochran-Armitage test was used to evaluate temporal trends. We used hospitalization data from the Canadian Institute for Health Information from 1996 to 2007 to confirm maternal mortality trends observed in the Vital Statistics data. RESULTS: Maternal mortality rates increased significantly from 4.5 (95% CI 3.3 to 5.8) in 1981 to 1983 to 4.7 (95% CI 3.5 to 6.2) in 1996 to 1998 and to 7.2 (95% CI 5.7 to 9.0) per 100 000 live births in 2005 to 2007 (P value for trend < 0.001). The most common causes of maternal death were diseases of the circulatory system, obstetric embolism (venous thromboembolism and amniotic fluid embolism), and hypertension. Deaths due to diseases of the circulatory system and puerperal infection increased significantly from 1981 to 2007. Maternal mortality rates in the hospitalization data were higher and did not show an increase over time. Provincial and territorial maternal mortality rates from Vital Statistics data showed varying degrees of under-ascertainment (12% to 70%) compared with hospitalization data. CONCLUSION: Temporal increases in maternal mortality in Canada observed in Vital Statistics data do not correspond with stable temporal trends observed in hospitalization data, and appear to be an artefact of changes in the coding and ascertainment of maternal deaths.

Temporal trends in maternal mortality in Canada II: estimates based on hospitalization data.

OBJECTIVES: World Health Organization reports based on Canadian Vital Statistics data suggest a recent increase in maternal mortality rates in Canada. Since Vital Statistics data typically provide inaccurate estimates of maternal mortality, we examined temporal trends in Canada using hospitalization data. METHODS: We identified in-hospital deaths among women aged 15 to 54 years from the Canadian Institute for Health Information's hospitalization database from 1996-1997 to 2007-2008. Maternal deaths during delivery were identified, and other in-hospital deaths were linked with prior pregnancy/delivery hospitalization records. Maternal mortality rates, 95% confidence intervals, and risk ratios (RRs) were estimated. RESULTS: The maternal mortality rate in Canada was 9.2 per 100 000 deliveries (95% CI 7.6 to 11.2) in 1996 to 1999 and 9.0 per 100 000 deliveries (95% CI 7.4 to 10.9) in 2005 to 2007 (P for trend = 0.22). Older maternal age (RR 9.9 and 3.1 for ≥ 45 years and 40 to 44 years vs. 20 to 24 years), delivery by Caesarean section (RR 4.5 vs. vaginal delivery), and early gestation delivery (RR 20.1 and 5.9 for 20 to 27 weeks and 28 to 36 weeks vs. ≥ 37 weeks) were associated with higher maternal mortality. Cardiovascular diseases (rate 4.7 per 100 000 deliveries, 95% CI 3.9 to 5.5) were the most common diagnoses associated with maternal death. The rate of late maternal death (from 43 to 365 days after delivery) was 5.4 per 100 000 deliveries. CONCLUSION: There was no increase in maternal mortality in Canada from 1996 to 2007. Increases observed in Canadian Vital Statistics data likely reflect improvements in the ascertainment of maternal death. Hospitalization data can serve as a timely and comprehensive source for monitoring trends in maternal mortality in Canada.

Use of routine interventions in labour and birth in Canadian hospitals: comparing results of the 1993 and 2007 Canadian hospital maternity policies and practices surveys.

OBJECTIVES: To compare policies and practices of routine interventions in labour and birth in Canadian hospitals in 1993 and 2007 and to describe trends regarding adherence to evidence-based guidelines. METHODS: We used data from surveys of Canadian hospitals in 1993 and 2007 on routine maternity care practices and policies, including interventions in labour and birth. RESULTS: The response rate of hospitals in 1993 was 91% (523/572), and in 2007 it was 92% (323/353). In 1993, 65% of hospitals (335/516) had a policy that all women should have initial electronic fetal heart rate monitoring, and in 2007, 74% (235/319) had such a policy. In 1993, 55% of hospitals (284/516) used epidural anaesthesia as one of the methods for pain control, and in 2007, 87% of hospitals (278/318) did so. In 1993, 37% of hospitals (193/521) had a "no enema/suppository" policy on admission, and in 2007, 88% (282/322) did. In 1993, 87% of hospitals (450/516) had a policy encouraging the presence of both the woman's partner and other labour support people in the room during the course of labour; in 2007, 80% (259/323) did. In 1993, hospitals estimated that 62% of primiparous women and 44% of multiparous women had an episiotomy in their units. In 2007, the episiotomy rate, irrespective of parity, was 17%. In 1993, 20% of hospitals (98/498) had a policy specifying the length of the second stage of labour, and in 2007, 33% (101/307) had such a policy. CONCLUSION: Positive and negative trends in adherence to best practices were seen in policies and practices of routine interventions during labour and birth in Canadian hospitals between 1993 and 2007.

Global epidemiology of hip fractures: a study protocol using a common analytical platform among multiple countries.

INTRODUCTION: Hip fractures are associated with a high burden of morbidity and mortality. Globally, there is wide variation in the incidence of hip fracture in people aged 50 years and older. Longitudinal and cross-geographical comparisons of health data can provide insights on aetiology, risk factors, and healthcare practices. However, systematic reviews of studies that use different methods and study periods do not permit direct comparison across geographical regions. Thus, the objective of this study is to investigate global secular trends in hip fracture incidence, mortality and use of postfracture pharmacological treatment across Asia, Oceania, North and South America, and Western and Northern Europe using a unified methodology applied to health records. METHODS AND ANALYSIS: This retrospective cohort study will use a common protocol and an analytical common data model approach to examine incidence of hip fracture across population-based databases in different geographical regions and healthcare settings. The study period will be from 2005 to 2018 subject to data availability in study sites. Patients aged 50 years and older and hospitalised due to hip fracture during the study period will be included. The primary outcome will be expressed as the annual incidence of hip fracture. Secondary outcomes will be the pharmacological treatment rate and mortality within 12 months following initial hip fracture by year. For the primary outcome, crude and standardised incidence of hip fracture will be reported. Linear regression will be used to test for time trends in the annual incidence. For secondary outcomes, the crude mortality and standardised mortality incidence will be reported. ETHICS AND DISSEMINATION: Each participating site will follow the relevant local ethics and regulatory frameworks for study approval. The results of the study will be submitted for peer-reviewed scientific publications and presented at scientific conferences.

Temporal trends and regional variations in severe maternal morbidity in Canada, 2003 to 2007.

OBJECTIVE: To identify temporal trends and regional variations in severe maternal morbidity in Canada using routine hospitalization data. METHODS: We used a previously identified set of International Statistical Classification of Diseases and Related Health Problems, 10th Revision (ICD-10CA) and Canadian Classification of Interventions (CCI) codes to estimate rates of severe maternal morbidity in Canada (excluding Quebec) for 2003 to 2007 using the Discharge Abstract Database of the Canadian Institute for Health Information (CIHI). Rates and 95% confidence intervals were calculated by year and within each province and territory and contrasted using the chi-square or Fisher exact test. RESULTS: The overall rate of severe maternal morbidity was 13.8 per 1000 deliveries (95% CI 13.6 to 14.0). Five provinces or territories had rates that were significantly higher than those in the rest of the country: Newfoundland and Labrador (19.0 per 1000; 95% CI 17.2 to 20.8), Saskatchewan (16.9 per 1000; 95% CI 15.9 to 18.0), Alberta (15.4 per 1000; 95% CI 14.9 to 15.9), Northwest Territories (22.5 per 1000; 95% CI 18.0 to 27.7), and Nunavut (20.2 per 1000; 95% CI 14.2 to 27.8). Rates of some illnesses declined (e.g., eclampsia rates decreased from 12.4 in 2003 to 5.7 per 10 000 deliveries in 2007, P<0.001), while others increased (e.g., postpartum hemorrhage with blood transfusion rates increased from 36.6 in 2003 to 44.3 per 10 000 deliveries in 2007, P<0.001). Interprovincial/territorial contrasts showed several disparities with respect to specific maternal illnesses. CONCLUSION: The observed temporal trends and regional disparities in severe maternal morbidity may represent important population health phenomena, and further investigation is required to assess their importance.

Trends in chronic disease incidence rates from the Canadian Chronic Disease Surveillance System. / Tendances des taux d'incidence des maladies chroniques d'après le Système canadien de surveillance des maladies chroniques.

INTRODUCTION: The Public Health Agency of Canada's Canadian Chronic Disease Surveillance System (CCDSS) produces population-based estimates of chronic disease prevalence and incidence using administrative health data. Our aim was to assess trends in incidence rates over time, trends are essential to understand changes in population risk and to inform policy development. METHODS: Incident cases of diagnosed asthma, chronic obstructive pulmonary disease (COPD), diabetes, hypertension, ischemic heart disease (IHD), and stroke were obtained from the CCDSS online infobase for 1999 to 2012. Trends in national and regional incidence estimates were tested using a negative binomial regression model with year as a linear predictor. Subsequently, models with year as a restricted cubic spline were used to test for departures from linearity using the likelihood ratio test. Age and sex were covariates in all models. RESULTS: Based on the models with year as a linear predictor, national incidence rates were estimated to have decreased over time for all diseases, except diabetes; regional incidence rates for most diseases and regions were also estimated to have decreased. However, likelihood ratio tests revealed statistically significant departures from a linear year effect for many diseases and regions, particularly for hypertension. CONCLUSION: Chronic disease incidence estimates based on CCDSS data are decreasing over time, but not at a constant rate. Further investigations are needed to assess if this decrease is associated with changes in health status, data quality, or physician practices. As well, population characteristics that may influence changing incidence trends also require exploration.

The Canadian Chronic Disease Surveillance System: A model for collaborative surveillance.

Chronic diseases have a major impact on populations and healthcare systems worldwide. Administrative health data are an ideal resource for chronic disease surveillance because they are population-based and routinely collected. For multi-jurisdictional surveillance, a distributed model is advantageous because it does not require individual-level data to be shared across jurisdictional boundaries. Our objective is to describe the process, structure, benefits, and challenges of a distributed model for chronic disease surveillance across all Canadian provinces and territories (P/Ts) using linked administrative data. The Public Health Agency of Canada (PHAC) established the Canadian Chronic Disease Surveillance System (CCDSS) in 2009 to facilitate standardized, national estimates of chronic disease prevalence, incidence, and outcomes. The CCDSS primarily relies on linked health insurance registration files, physician billing claims, and hospital discharge abstracts. Standardized case definitions and common analytic protocols are applied to the data for each P/T; aggregate data are shared with PHAC and summarized for reports and open access data initiatives. Advantages of this distributed model include: it uses the rich data resources available in all P/Ts; it supports chronic disease surveillance capacity building in all P/Ts; and changes in surveillance methodology can be easily developed by PHAC and implemented by the P/Ts. However, there are challenges: heterogeneity in administrative databases across jurisdictions and changes in data quality over time threaten the production of standardized disease estimates; a limited set of databases are common to all P/Ts, which hinders potential CCDSS expansion; and there is a need to balance comprehensive reporting with P/T disclosure requirements to protect privacy. The CCDSS distributed model for chronic disease surveillance has been successfully implemented and sustained by PHAC and its P/T partners. Many lessons have been learned about national surveillance involving jurisdictions that are heterogeneous with respect to healthcare databases, expertise and analytical capacity, population characteristics, and priorities.

Delivery of breech presentation at term gestation in Canada, 2003-2011.

OBJECTIVE: To examine neonatal mortality and morbidity rates by mode of delivery among women with breech presentation at term gestation. METHODS: We carried out a population-based cohort study examining neonatal outcomes among term, nonanomalous singletons in breech presentation among all hospital deliveries in Canada (excluding Quebec) between 2003 and 2011. Mode of delivery was categorized into vaginal delivery, cesarean delivery in labor, and cesarean delivery without labor. Composite neonatal mortality and morbidity (death, assisted ventilation, convulsions, or specific birth injury) was the primary outcome. Logistic regression was used to estimate the independent effects of mode of delivery. RESULTS: The study population included 52,671 breech deliveries; vaginal deliveries increased from 2.7% in 2003 to 3.9% in 2011, and cesarean deliveries in labor increased from 8.7% to 9.8%. Composite neonatal mortality and morbidity rates at 37 weeks of gestation or greater after vaginal delivery were significantly higher than those after cesarean without labor (adjusted rate ratio 3.60, 95% confidence interval [CI] 2.50-5.15; adjusted rate difference 15.8/1,000 deliveries, 95% CI 9.2-25.2). Among women at 40 weeks of gestation or greater, neonatal mortality and morbidity rates after vaginal delivery were significantly higher than those after cesarean delivery without labor (adjusted rate ratio 5.39, 95% CI 2.68-10.8; adjusted rate difference 24.1/1,000 deliveries, 95% CI 9.2-53.8). Neonatal mortality and morbidity rates were also higher after caesarean delivery in labor. CONCLUSION: Among term, nonanomalous singletons in breech presentation at term, composite neonatal mortality and morbidity rates were significantly higher after vaginal delivery and cesarean delivery in labor compared with cesarean delivery without labor. LEVEL OF EVIDENCE: II.

Once more unto the breech: planned vaginal delivery compared with planned cesarean delivery.

This article provides a knowledge-based assessment of planned cesarean delivery compared with planned vaginal delivery for breech presentation at term gestation. The most critical evidence on this issue is the intention-to-treat analysis from the Term Breech Trial, which showed that planned cesarean delivery reduced composite perinatal death and serious neonatal morbidity. Although there was no difference in composite death or neurodevelopmental delay at 2 years of age, this finding was based on only 44% of randomized patients and was not an analysis by intention to treat. On the other hand, the design of the nonexperimental Presentation et Mode d'Accouchement: presentation and mode of delivery (PREMODA) study (which showed no difference in composite perinatal mortality or morbidity after planned cesarean delivery compared with planned vaginal delivery), likely favored the planned vaginal delivery group; lack of exclusion criteria led to higher risk women (with contraindications to vaginal delivery) being included in the planned cesarean delivery group. Such selection bias notwithstanding, both the Term Breech Trial and the PREMODA study showed significantly higher rates of 5-minute Apgar score less than 4, 5-minute Apgar score less than 7, intubation, and birth trauma in the planned vaginal delivery group. Finally, studies from the Netherlands, Denmark, and Canada have shown that increases in planned cesarean delivery after the Term Breech Trial led to improved neonatal outcomes. Nevertheless, planned vaginal delivery continues to be associated with higher rates of adverse perinatal outcomes in these countries. The totality of the evidence therefore unequivocally shows the relatively greater safety of planned cesarean delivery for breech presentation at term gestation.

Contribution of placenta accreta to the incidence of postpartum hemorrhage and severe postpartum hemorrhage.

OBJECTIVE: To quantify the contribution of placenta accreta to the rate of postpartum hemorrhage and severe postpartum hemorrhage. METHODS: All hospital deliveries in Canada (excluding Quebec) for the years 2009 and 2010 (N=570,637) were included in a retrospective cohort study using data from the Canadian Institute for Health Information. Placenta accreta included placental adhesion to the uterine wall, musculature, and surrounding organs (accreta, increta, or percreta). Severe postpartum hemorrhage included postpartum hemorrhage with blood transfusion, hysterectomy, or other procedures to control bleeding (including uterine suturing and ligation or embolization of pelvic arteries). Rates, rate ratios, population-attributable fractions (ie, incidence of postpartum hemorrhage attributable to placenta accreta), and 95% confidence intervals (CIs) were estimated. Logistic regression was used to quantify associations between placenta accreta and risk factors. RESULTS: The incidence of placenta accreta was 14.4 (95% CI 13.4-15.4) per 10,000 deliveries (819 cases among 570,637 deliveries), whereas the incidence of placenta accreta with postpartum hemorrhage was 7.2 (95% CI 6.5-8.0) per 10,000 deliveries. Postpartum hemorrhage among women with placenta accreta was predominantly third-stage hemorrhage (41% of all cases). Although placenta accreta was strongly associated with postpartum hemorrhage (rate ratio 8.3, 95% CI 7.7-8.9), its low frequency resulted in a small population-attributable fraction (1.0%, 95% CI 0.93-1.16). However, the strong association between placenta accreta and postpartum hemorrhage with hysterectomy (rate ratio 286, 95% CI 226-361) resulted in a population-attributable fraction of 29.0% (95% CI 24.3-34.3). CONCLUSION: Placenta accreta is too infrequent to account for the recent temporal increase in postpartum hemorrhage but contributes substantially to the proportion of postpartum hemorrhage with hysterectomy.

Hypertensive disorders of pregnancy and the recent increase in obstetric acute renal failure in Canada: population based retrospective cohort study.

OBJECTIVE: To examine whether changes in postpartum haemorrhage, hypertensive disorders of pregnancy, or other risk factors explain the increase in obstetric acute renal failure in Canada. DESIGN: Retrospective cohort study. SETTING: Canada (excluding the province of Quebec). PARTICIPANTS: All hospital deliveries from 2003 to 2010 (n=2,193,425). MAIN OUTCOME MEASURES: Obstetric acute renal failure identified by ICD-10 diagnostic codes. METHODS: Information on all hospital deliveries in Canada (excluding Quebec) between 2003 and 2010 (n=2,193,425) was obtained from the Canadian Institute for Health Information. Temporal trends in obstetric acute renal failure were assessed among women with and without postpartum haemorrhage, hypertensive disorders of pregnancy, or other risk factors. Logistic regression was used to determine if changes in risk factors explained the temporal increase in obstetric acute renal failure. RESULTS: Rates of obstetric acute renal failure rose from 1.66 to 2.68 per 10,000 deliveries between 2003-04 and 2009-10 (61% increase, 95% confidence interval 24% to 110%). Adjustment for postpartum haemorrhage, hypertensive disorders, and other factors did not attenuate the increase. The temporal increase in acute renal failure was restricted to deliveries with hypertensive disorders (adjusted increase 95%, 95% confidence interval 38% to 176%), and was especially pronounced among women with gestational hypertension with significant proteinuria (adjusted increase 171%, 71% to 329%). No significant increase occurred among women without hypertensive disorders (adjusted increase 12%, -28 to 72%). CONCLUSIONS: The increase in obstetric acute renal failure in Canada between 2003 and 2010 was restricted to women with hypertensive disorders and was especially pronounced among women with pre-eclampsia. Further study is required to determine the cause of the increase among women with pre-eclampsia.