Multisystem inflammatory syndrome in 1.2 million children: longitudinal cohort study of risk factors.

BACKGROUND: We identified patient characteristics associated with an increased risk of developing MIS-C. METHODS: We conducted a longitudinal cohort study of 1,195,327 patients aged 0-19 years between 2006 and 2021, including the first two waves of the pandemic (February 25-August 22, 2020 and August 23, 2020-March 31, 2021). Exposures included prepandemic morbidity, birth outcomes, and family history of maternal disorders. Outcomes included MIS-C, Kawasaki disease, and other Covid-19 complications during the pandemic. We calculated risk ratios (RRs) and 95% confidence intervals (CIs) for the association between patient exposures and these outcomes using log-binomial regression models adjusted for potential confounders. RESULTS: Among 1,195,327 children, 84 developed MIS-C, 107 Kawasaki disease, and 330 other Covid-19 complications during the first year of the pandemic. Prepandemic hospitalizations for metabolic disorders (RR 11.3, 95% CI 5.61-22.6), atopic conditions (RR 3.34, 95% CI 1.60-6.97), and cancer (RR 8.11, 95% CI 1.13-58.3) were strongly associated with the risk of MIS-C, compared with no exposure. These same exposures were also associated with Kawasaki disease and other Covid-19 complications. However, birth characteristics and history of maternal morbidity were not associated with MIS-C development. CONCLUSIONS: Children with pre-existing morbidity have a considerably elevated risk of MIS-C. IMPACT: Morbidities that predispose children to multisystem inflammatory syndrome (MIS-C) are unclear. In this study, prepandemic hospitalizations for metabolic disorders, atopic conditions, and cancer were associated with an elevated risk of MIS-C. Birth characteristics and family history of maternal morbidity were not, however, associated with MIS-C. Pediatric morbidities may play a greater role in MIS-C onset than maternal or perinatal characteristics, and may help clinicians better recognize children at risk for this complication.

Congenital anomalies during Covid-19: artifact of surveillance or a real TORCH?

Infections in the first trimester of pregnancy can be teratogenic, but the possibility that Covid-19 could lead to birth defects is unclear. We examined whether SARS-CoV-2 infection during pregnancy or exposure to pandemic conditions were associated with the risk of congenital anomalies. We carried out a retrospective study of 420,222 neonates born in Quebec, Canada in two time periods: prepandemic (January 1, 2017 to March 12, 2020) vs. pandemic (March 13, 2020 to March 31, 2022). We classified pandemic births as early (first trimester completed before the pandemic) or late (first trimester during the pandemic), and identified patients with SARS-CoV-2 infections during pregnancy. We applied (1) adjusted log-binomial regression models to assess the association between SARS-CoV-2 infection and congenital anomalies, and (2) autoregressive interrupted time series regression to analyze temporal trends in the monthly number of defects in all patients regardless of infection. In total, 29,263 newborns (7.0%) had a congenital anomaly. First trimester SARS-CoV-2 infections were not associated with a greater risk of birth defects compared with no infection (RR 1.07, 95% CI 0.59-1.95). However, births during the late pandemic period were more likely to be diagnosed with congenital microcephaly compared with prepandemic births (RR 1.44, 95% CI 1.21-1.71). Interrupted time series analysis confirmed that the frequency of microcephaly increased during the late pandemic period, whereas other anomalies did not. We conclude that Covid-19 is likely not teratogenic, but enhanced surveillance of anomalies among late pandemic births may have heightened the detection of infants with microcephaly.

Hyperemesis gravidarum and the risk of offspring morbidity: a longitudinal cohort study.

PURPOSE: Hyperemesis gravidarum has the potential to affect the long-term health of offspring. We examined whether maternal hyperemesis gravidarum was associated with the risk of hospitalization for childhood morbidity. METHODS: We conducted a longitudinal cohort study of 1,189,000 children born in Quebec, Canada, between April 2006 and March 2021. The main exposure measure was maternal hyperemesis gravidarum requiring hospitalization in the first or second trimester. The outcome was any pediatric admission between birth and 16 years of age, with follow-up ending in March 2022. We used Cox regression models adjusted for maternal and socioeconomic factors to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association between maternal hyperemesis gravidarum and childhood hospitalization. RESULTS: Among 1,189,000 children, 6904 (0.6%) were exposed to maternal hyperemesis gravidarum. Hospitalization rates at age 16 years were higher for children exposed to hyperemesis gravidarum than unexposed children (47.6 vs 43.9 per 100 children). Relative to no exposure, hyperemesis gravidarum was associated with a 1.21 times greater risk of any hospitalization before 16 years (95% CI 1.17-1.26). Hyperemesis gravidarum was associated with hospitalization for neurologic (HR 1.50, 95% CI 1.32-1.71), developmental (HR 1.51, 95% CI 1.29-1.76), digestive (HR 1.40, 95% CI 1.30-1.52), and allergic disorders (HR 1.39, 95% CI 1.24-1.56). When contrasted with preeclampsia, hyperemesis gravidarum was a stronger risk factor for these outcomes. CONCLUSIONS: Maternal hyperemesis gravidarum is associated with an increased risk of childhood hospitalization, especially for neurologic, developmental, digestive, and atopic disorders. WHAT IS KNOWN: • Hyperemesis gravidarum is associated with neurodevelopmental disorders in offspring. • However, the effect of hyperemesis gravidarum on other childhood morbidity is unclear. WHAT IS NEW: • In this longitudinal cohort study of 1.2 million children, maternal hyperemesis gravidarum was associated with a greater risk of hospitalization before age 16 years. • Exposure to hyperemesis gravidarum was associated with developmental, neurologic, atopic, and digestive morbidity in childhood.

Extended Risk of Mortality in Children with Inborn Errors of Metabolism: A Longitudinal Cohort Study.

OBJECTIVES: To determine the long-term risk of mortality among children with inborn errors of metabolism. STUDY DESIGN: We conducted a retrospective cohort study of 1750 children with inborn errors of metabolism (excluding mitochondrial disorders) and 1 036 668 children without errors of metabolism who were born in Quebec, Canada, between 2006 and 2019. Main outcome measures included all-cause and cause-specific mortality between birth and 14 years of age. We used adjusted survival regression models to estimate HRs and 95% CIs for the association between inborn errors of metabolism and mortality over time. RESULTS: Mortality rates were greater for children with errors of metabolism than for unaffected children (69.1 vs 3.2 deaths per 10 000 person-years). During 7 702 179 person-years of follow-up, inborn errors of metabolism were associated with 21.2 times the risk of mortality compared with no error of metabolism (95% CI 17.23-26.11). Disorders of mineral metabolism were associated with greater mortality the first 28 days of life (HR 60.62, 95% CI 10.04-365.98), and disorders of sphingolipid metabolism were associated with greater mortality by 1 year (HR 284.73, 95% CI 139.20-582.44) and 14 years (HR 1066.00, 95% CI 298.91-3801.63). Errors of metabolism were disproportionately associated with death from hepatic/digestive (HR 208.21, 95% CI 90.28-480.22), respiratory (HR 116.57, 95% CI 71.06-191.23), and infectious causes (HR 119.83, 95% CI 40.56-354.04). CONCLUSIONS: Children with errors of metabolism have a considerably elevated risk of mortality before 14 years, including death from hepatic/digestive, respiratory, and infectious causes. Targeting these causes of death may help improve long-term survival.

Second-trimester abortion and risk of live birth.

BACKGROUND: Second-trimester abortion may result in a live birth, but the extent to which this outcome occurs is unknown. OBJECTIVE: This study aimed to examine rates of live birth after pregnancy termination in the second trimester and identify associated risk factors. STUDY DESIGN: We conducted a retrospective cohort study of 13,777 second-trimester abortions occurring in hospital settings between April 1, 1989 and March 31, 2021 in Quebec, Canada. The exposure was induced abortion between 15 and 29 weeks of gestation, including the indication for (fetal anomaly, maternal emergency, other) and use of feticidal injection (intracardiac/intrathoracic or intraamniotic). The primary outcome was live birth following abortion. We measured the rate of live birth per 100 abortions and used adjusted log-binomial regression models to estimate risk ratios and 95% confidence intervals for the association of fetal and maternal characteristics with the risk of live birth. We assessed the extent to which feticidal injection reduced the risk. RESULTS: Among 13,777 abortions between 15 and 29 weeks of gestation, 1541 (11.2%) led to live birth. Fetal anomaly was a common indication for termination (48.1%), and most abortions were by labor induction (72.2%). Compared with abortion between 15 and 19 weeks, abortion between 20 and 24 weeks was associated with 4.80 times the risk of live birth (95% confidence interval, 4.20-5.48), whereas abortion between 25 and 29 weeks was associated with 1.34 times the risk (95% confidence interval, 1.00-1.79). Feticidal injection reduced the risk of live birth by 57% compared with no injection (risk ratio, 0.43; 95% confidence interval, 0.36-0.51). Intracardiac or intrathoracic injection was particularly effective at preventing live birth (risk ratio, 0.02; 95% confidence interval, 0.01-0.07). CONCLUSION: Second-trimester abortion carries a risk of live birth, especially at 20 to 24 weeks of gestation, although feticidal injection may protect against this outcome.

Shifting age of child eating disorder hospitalizations during the Covid-19 pandemic.

BACKGROUND: We studied the effect of the Covid-19 pandemic on child eating disorder hospitalizations in Quebec, Canada. Quebec had one of the strictest lockdown measures targeting young people in North America. METHODS: We analyzed eating disorder hospitalizations in children aged 10-19 years before and during the pandemic. We used interrupted time series regression to assess trends in the monthly number of hospitalizations for anorexia nervosa, bulimia nervosa, and other eating disorders before the pandemic (April 2006 to February 2020), and during the first (March to August 2020) and second waves (September 2020 to March 2021). We determined the types of eating disorders requiring hospital treatment and identified the age, sex and socioeconomic subgroups that were most affected. RESULTS: Hospitalization rates for eating disorders increased during the first (6.5 per 10,000) and second waves (12.8 per 10,000) compared with the period before the pandemic (5.8 per 10,000). The increase occurred for anorexia nervosa as well as other types of eating disorders. The number of girls and boys aged 10-14 years admitted for eating disorders increased during wave 1. Wave 2 triggered an increase in eating disorder admissions among girls aged 15-19 years. Hospitalization rates increased earlier for advantaged than disadvantaged youth. CONCLUSIONS: The Covid-19 pandemic affected hospitalizations for anorexia nervosa as well as other eating disorders, beginning with girls aged 10-14 years during wave 1, followed by girls aged 15-19 years during wave 2. Boys aged 10-14 years were also affected, as well as both advantaged and disadvantaged youth.

Observational study of birth outcomes in children with inborn errors of metabolism.

BACKGROUND: We examined the birth outcomes of children with inborn errors of metabolism detected at birth or later in life. METHODS: We carried out a retrospective cohort study of 1733 children with inborn errors of metabolism and 1,033,693 unaffected children born in Canada between 2006 and 2019. Primary outcomes included preterm birth, low birth weight, congenital anomalies, and other neonatal complications. We estimated adjusted risk ratios (RR) and 95% confidence intervals (CI) for the association of inborn errors of metabolism with each outcome. RESULTS: Children with inborn errors of metabolism had 2.51 times the risk of preterm birth (95% CI 2.27-2.77) and 3.08 times the risk of low birth weight (95% CI 2.77-3.42) compared with unaffected children. Disorders of mineral and lipoprotein metabolism were more strongly associated with adverse birth outcomes. Inborn errors of metabolism were associated with congenital anomalies (RR 2.62; 95% CI 2.36-2.90), particularly abdominal wall defects (RR 8.35; 95% CI 5.18-13.44). Associations were present for errors of metabolism diagnosed both at birth and later in life. CONCLUSIONS: Children with inborn errors of metabolism, whether detected at birth or later, are at high risk of adverse birth outcomes and congenital anomalies. IMPACT: Inborn errors of metabolism may affect fetal development, but the association with adverse birth outcomes is not well characterized. This study indicates that children with inborn errors of metabolism are at risk of preterm birth, neonatal jaundice, congenital anomalies, and a range of other adverse birth outcomes. Mothers of children with inborn errors of metabolism are at risk of preeclampsia and cesarean delivery. Adverse birth outcomes may be a first sign of inborn errors of metabolism that merit increased screening.

Risk of congenital anomalies in children who have a sibling with cancer: A matched cohort study.

PURPOSE: We assessed the risk of congenital anomalies in children who have a sibling with cancer. METHODS: We performed a matched cohort study of children born between 2006 and 2022 in Quebec. The exposure was having a sibling with cancer. Exposed children were matched to unexposed children based on sex, number of siblings, birth order, and year. The outcome included heart defects, orofacial clefts, and other anomalies. Using conditional logistic regression, we estimated odds ratios (OR) and 95 % confidence intervals (CI) for the association between having a sibling with cancer and the likelihood of having a congenital anomaly. RESULTS: A total of 2403 children who had a sibling with cancer were matched to 240,257 unexposed children. Congenital anomalies were more frequent in children who had a sibling with cancer compared with unexposed children (10.3 % vs 8.9 %). Overall, having a sibling with cancer was only weakly associated with congenital anomalies (OR 1.18, 95 % CI 1.04-1.35). Exposed children tended to have greater odds of polydactyly/syndactyly (OR 1.89, 95 % CI 1.11-3.21) and urinary defects (OR 1.50, 95 % CI 1.09-2.08) compared with unexposed children. CONCLUSIONS: Children who have a sibling with cancer have an only weakly elevated risk of congenital anomalies.

Inequality in COVID-19 mortality in Quebec associated with neighbourhood-level vulnerability domains.

OBJECTIVES: We measured disparities in COVID-19 mortality associated with increasing vulnerability to severe outcomes of infectious disease at the neighbourhood level to identify domains for prioritization of public interventions. METHODS: In this retrospective ecological study, we calculated COVID-19 mortality rate ratios (RR) comparing neighbourhoods with the greatest vulnerability relative to lowest vulnerability using the five domains from the COVID-19 vulnerability index for Quebec using hospital data from the first year of the pandemic and vulnerability levels from 13,182 neighbourhoods. We estimated the attributable fraction to assess disparities in COVID-19 mortality associated with vulnerability. Domains covered biological susceptibility, sociocultural characteristics, socioeconomic characteristics, and indoor and outdoor risk factors for exposure to SARS-CoV-2. RESULTS: Vulnerable neighbourhoods accounted for 60.7% of COVID-19 deaths between March 2020 and February 2021. Neighbourhoods with biological susceptibility accounted for 46.1% and indoor exposure for 44.6% of deaths. Neighbourhoods with socioeconomic vulnerability experienced 23.5%, outdoor exposure 14.6%, and sociocultural vulnerability 9.0% of deaths. Neighbourhoods with high relative vulnerability had 4.66 times greater risk of COVID-19 mortality compared with those with low vulnerability (95%CI 3.82-5.67). High vulnerability in the biological (RR 3.33; 95%CI 2.71-4.09), sociocultural (RR 1.50; 95%CI 1.27-1.77), socioeconomic (RR 2.08; 95%CI 1.75-2.48), and indoor (RR 3.21; 95%CI 2.74-3.76) exposure domains were associated with elevated risks of mortality compared with the least vulnerable neighbourhoods. Outdoor exposure was unassociated with mortality (RR 1.17; 95%CI 0.96-2.43). CONCLUSION: Public intervention to protect vulnerable populations should be adapted to focus on domains most associated with COVID-19 mortality to ensure addressing local needs.

RéSUMé: OBJECTIFS: Nous avons mesuré les inégalités de mortalité de COVID-19 associées à la vulnérabilité croissante des conséquences sévères de maladies infectieuses au Québec. L'échelle de quartier permet d'identifier des domaines à prioriser lors d'interventions publiques. MéTHODES: Dans cette étude écologique rétrospective, nous avons calculé des ratios des taux (RT) en comparant les territoires de plus grande vulnérabilité avec ceux de plus faible vulnérabilité à l'aide de données d'hospitalisation de la première année de la pandémie et de mesures de vulnérabilité de 13 182 aires de diffusion (AD). Nous avons estimé la fraction attribuable pour évaluer les disparités de mortalité par la COVID-19. Les domaines examinés concernaient la susceptibilité biologique, les caractéristiques socioculturelles et socioéconomiques ainsi que des facteurs de risque d'exposition au SRAS-CoV-2 à l'intérieur et à l'extérieur. RéSULTATS: Dans l'ensemble, les territoires vulnérables couvraient 60,7 % des cas de mortalité de COVID-19 pendant la première année de la pandémie. Les AD avec une vulnérabilité élevée avaient un risque de mortalité par la COVID-19 4,66 fois plus élevé comparé aux territoires de faible vulnérabilité (IC de 95% 3,82-5,67). Les aires de diffusion avec une susceptibilité biologique comptaient pour 46,1 % des décès et celles avec une exposition au SRAS-CoV-2 à l'intérieur pour 44,6 %. La vulnérabilité socioéconomique comptait pour 23,5 %, l'exposition à l'extérieur pour 14,6 %, et la vulnérabilité socioculturelle pour 9,0 % des décès. Les domaines biologique (RT 3,33; IC de 95% 2,71-4,09), socioculturel (RT 1,50; IC de 95% 1,27-1,77), socioéconomique (RT 2,08; IC de 95% 1,75-2,48), et d'exposition intérieure (RT 3,21; IC de 95% 2,74-3,76) étaient associés à un risque élevé de mortalité par la COVID-19 comparé aux territoires les moins vulnérables. L'exposition extérieure n'était pas associée avec un risque de mortalité par la COVID-19 (RT 1,17; IC de 95% 0,96-2,43). CONCLUSION: Les interventions publiques visant à protéger les populations vulnérables devraient être adaptées aux domaines les plus associés avec la mortalité par la COVID-19 au Québec et ce, à l'échelle de quartier pour s'assurer que les besoins locaux soient couverts.

Long-term outcomes of patients with toxic shock syndrome: A matched cohort study.

OBJECTIVES: We examined long-term outcomes of toxic shock syndrome. METHODS: We conducted a matched cohort study of 630 patients with toxic shock syndrome and 5009 healthy controls between 2006 and 2021 in Quebec, Canada. Outcomes included hospitalization for renal, cardiovascular, hepatic, and other morbidity during 15 years of follow-up. We estimated adjusted hazard ratios (HR) and 95% confidence intervals (CI) for the risk of these outcomes over time, comparing patients with toxic shock syndrome relative to matched controls. RESULTS: Compared with healthy controls, rehospitalization rates at 15 years were higher for men with toxic shock syndrome (52.0 vs 30.0 per 100) but not for women (38.7 vs 45.6 per 100). In men, toxic shock syndrome was associated with an elevated risk of renal (HR 17.43, 95% CI 6.35-47.82), cardiovascular (HR 2.57; 95% CI 1.52-4.34), and hepatic hospitalization (HR 19.83, 95% CI 4.72-83.34). In women, toxic shock syndrome was associated with renal hospitalization (HR 4.71, 95% CI 1.94-11.45). Streptococcal toxic shock was associated with a greater risk of rehospitalization than staphylococcal toxic shock. CONCLUSIONS: Toxic shock syndrome is associated with rehospitalization up to 15 years later, especially in men. These patients may benefit from continued follow-up to prevent long-term morbidity.

Lockdowns and cycling injuries: temporal analysis of rates in Quebec during the first year of the pandemic. / Les confinements et les blessures à vélo : une analyse temporelle des taux de blessures au Québec au cours de la première année de la pandémie.

INTRODUCTION: Cycling increased in popularity during the COVID-19 pandemic, but the impact on cycling injuries is not known. We examined the effect of lockdowns on cycling injury hospitalizations. METHODS: We identified hospitalizations for cycling injuries in Quebec, Canada, between April 2006 and March 2021. We used rate ratios (RR) and 95% confidence intervals (CI) to compare hospitalization rates by type of cycling injury and anatomical site during two waves of the pandemic. We performed interrupted time series regression to assess the effect of lockdowns on monthly cycling injury hospitalization rates, according to age, sex and other characteristics. RESULTS: There were 2020 hospitalizations for cycling injuries between March 2020 and March 2021, including 617 during the first lockdown and 67 during the second lockdown. Compared with the period before the pandemic, risk of cycling-related injuries during the first lockdown increased the most for fractures (RR = 1.44; 95% CI: 1.26- 1.64) and head and neck injuries (RR = 1.59; 95% CI: 1.19-2.12). Cycling injury hospitalization rates increased significantly among adults, adolescents and individuals from socioeconomically advantaged neighbourhoods or those with low concentrations of racialized people every month of the first lockdown. The second lockdown was not associated with cycling injuries. CONCLUSION: The first lockdown triggered a sharp increase in cycling injury hospitalizations, especially among adults, adolescents and individuals from socioeconomically advantaged and less racialized neighbourhoods.

Multisystem inflammatory syndrome in adults: Comparison with other inflammatory conditions during the Covid-19 pandemic.

BACKGROUND: Multisystem inflammatory syndrome in adults (MIS-A) is an increasingly recognized complication of Covid-19. We assessed risk factors, clinical characteristics, and outcomes of patients with MIS-A compared with other inflammatory conditions. METHODS: We analyzed a cohort of patients ≥21 years hospitalized with MIS-A in Quebec, Canada between February 2020 and March 2021. We included comparison groups that share symptomatology or pathophysiology with MIS-A, including Kawasaki disease, toxic shock syndrome, and other Covid-19 complications. We examined characteristics of men and women at admission, and identified preexisting factors associated with MIS-A through odds ratios (OR) and 95% confidence intervals (CI) from adjusted logistic regression models. RESULTS: Among 22,251 patients in this study, 52 had MIS-A, 90 Kawasaki disease, 500 toxic shock syndrome, and 21,609 other Covid-19 complications. MIS-A was associated with an elevated risk of respiratory failure compared with Kawasaki disease (OR 7.22, 95% CI 1.26-41.24), toxic shock syndrome (OR 4.41, 95% CI 1.73-11.23), and other Covid-19 complications (OR 3.03, 95% CI 1.67-5.50). Patients with MIS-A had a greater risk of cardiac involvement, renal failure, and mortality. The data pointed towards sex-specific differences in presentation, with more respiratory involvement in women and cardiac involvement in men compared with patients that had other Covid-19 complications. Except for allergic disorders and cancer, prior medical risk factors were not associated with a greater likelihood of MIS-A. CONCLUSIONS: Patients with MIS-A have an elevated risk of mortality compared with other inflammatory conditions, with women having a predominance of respiratory complications and men cardiovascular complications.

Risk of Cardiovascular Disease in Women With a History of Hyperemesis Gravidarum, With and Without Preeclampsia.

Background Hyperemesis gravidarum is associated with preeclampsia, but it is unclear whether hyperemesis gravidarum is a risk factor for cardiovascular disease. We assessed the long-term risk of cardiovascular disease in women who experienced hyperemesis gravidarum with or without preeclampsia. Methods and Results We analyzed a longitudinal cohort of 1 413 166 pregnant women in Quebec between 1989 and 2021. Women were followed from their first pregnancy up to 3 decades later. We computed hazard ratios (HRs) and 95% CIs for the association of hyperemesis gravidarum, preeclampsia, or both conditions with subsequent risk of cardiovascular hospitalization using Cox regression models adjusted for baseline characteristics. Among 1 413 166 women, 16 288 (1.2%) had hyperemesis gravidarum only, 69 645 (4.9%) preeclampsia only, and 1103 (0.08%) had both conditions. After 32 years of follow-up, cardiovascular disease incidence was 17.7 per 100 women with hyperemesis gravidarum only, 28.2 per 100 women with preeclampsia only, 30.9 per 100 women with both exposures, and 14.0 per 100 women with neither exposure. Compared with no exposure, women with both hyperemesis and preeclampsia had the greatest risk of cardiovascular hospitalization (HR, 3.54 [95% CI, 3.03-4.14]), followed by women with preeclampsia only (HR, 2.58 [95% CI, 2.51-2.64]) and hyperemesis only (HR, 1.46 [95% CI, 1.38-1.54]). Having both hyperemesis gravidarum and preeclampsia was strongly associated with valve disease (HR, 3.38 [95% CI, 1.69-6.75]), heart failure (HR, 3.43 [95% CI, 1.79-6.59]), and cardiomyopathy (HR, 4.17 [95% CI, 1.99-8.76]). Conclusions Hyperemesis gravidarum is associated with the development of cardiovascular disease, whether preeclampsia is present or not.

Hospitalization for child maltreatment and other types of injury during the COVID-19 pandemic.

BACKGROUND: The possibility that child maltreatment was misclassified as unintentional injury during the COVID-19 pandemic has not been evaluated. OBJECTIVE: We assessed if child maltreatment hospitalizations changed during the pandemic, and if the change was accompanied by an increase in unintentional injuries. PARTICIPANTS AND SETTING: This study included children aged 0-4 years who were admitted for maltreatment or unintentional injuries between April 2006 and March 2021 in hospitals of Quebec, Canada. METHODS: We used interrupted time series regression to estimate the effect of the pandemic on hospitalization rates for maltreatment, compared with unintentional transport accidents, falls, and mechanical force injuries. We assessed if the change in maltreatment hospitalization was accompanied by an increase in specific types of unintentional injury. RESULTS: Hospitalizations for child maltreatment decreased from 16.3 per 100,000 (95 % CI 9.1-23.4) the year before the pandemic to 13.2 per 100,000 (95 % CI 6.7-19.7) during the first lockdown. Hospitalizations for most types of unintentional injury also decreased, but injuries due to falls involving another person increased from 9.0 to 16.5 per 100,000. Hospitalization rates for maltreatment and unintentional injury remained low during the second lockdown, but mechanical force injuries involving another person increased from 3.8 to 8.1 per 100,000. CONCLUSIONS: Hospitalizations for child maltreatment may have been misclassified as unintentional injuries involving another person during the pandemic. Children admitted for these types of unintentional injuries may benefit from closer assessment to rule out maltreatment.

Suicide Attempt and Risk of Substance Use Disorders Among Female Youths.

Importance: Suicide attempts are prevalent among female youths, yet little is known about the subsequent development of substance use disorders. Objective: To assess the association between suicide attempts among females before 20 years of age and future risk of substance use disorders. Design, Setting, and Participants: In this longitudinal cohort study, females aged 8 to 19 years (hereafter referred to as youths) who attempted suicide were matched with female youths with no attempt between April 1, 1989, and March 31, 2019, in Quebec, Canada. The cohort was followed up for 31 years, for a total of 2 409 396 person-years, to identify subsequent substance use disorders. Exposures: Confirmed suicide attempts among females 8 to 19 years of age. Main Outcomes and Measures: The main outcome measure was hospitalization for a substance use disorder later in life. Hazard ratios (HRs) and 95% CIs for the association of suicide attempt with substance use disorders were estimated using Cox proportional hazards regression models adjusted for baseline age, mental illness, resource-limited socioeconomic status, and year at start of follow-up. Results: Among 122 234 female youths (mean [SD] age, 15.6 [1.9] years), 5840 (4.8%) attempted suicide and 4341 (3.6%) developed a substance use disorder. Compared with the 116 394 matched female youths who did not attempt suicide (95.2%), those who attempted suicide had a greater risk of hospitalization for any substance use disorder during the follow-up period (HR, 6.03; 95% CI, 5.39-6.77), especially sedative or hypnotic use disorders (HR, 32.24; 95% CI, 23.29-44.64). Suicide attempt was associated with the development of sedative or hypnotic use disorders up to 5 years (HR, 66.69; 95% CI, 34.72-128.09), although risks remained elevated up to 3 decades later for all substances. Compared with those without suicide attempt, female youths with 3 or more suicide attempts had 21.20 (95% CI, 13.53-32.90) times the risk of substance use disorders, whereas female youths with 1 attempt had 5.70 (95% CI, 5.08-6.41) times the risk of these disorders. Conclusions and Relevance: In this cohort study, female youths who attempted suicide had increased risk of subsequent substance use disorders compared with female youths who did not attempt suicide. These findings suggest that closer management and prevention of substance use among female youths who attempt suicide may be beneficial.