Unexposed Cohort Research Articles

Pregnancy outcomes in the omalizumab pregnancy registry and a disease-matched comparator cohort

The Observational Study of the Use and Safety of Xolair (omalizumab) during Pregnancy (EXPECT) pregnancy registry was a prospective observational study established in 2006 to evaluate perinatal outcomes in pregnant women exposed to omalizumab and their infants. This analysis compares EXPECT outcomes with those from a disease-matched population of pregnant women not treated with omalizumab. Data from a substudy of platelet counts among newborns are also presented. The EXPECT study enrolled 250 women with asthma exposed to omalizumab during pregnancy. The disease-matched external comparator cohort of women with moderate-to-severe asthma (n=1153), termed the Quebec External Comparator Cohort (QECC), was created by using data from health care databases in Quebec, Canada. Outcome estimates were age adjusted based on the maternal age distribution of the EXPECT study. Among singleton infants in the EXPECT study, the prevalence of major congenital anomalies was 8.1%, which was similar to the 8.9% seen in the QECC. In the EXPECT study 99.1% of pregnancies resulted in live births, which was similar to 99.3% in the QECC. Premature birth was identified in 15.0% of EXPECT infants and 11.3% in the QECC. Small for gestational age was identified in 9.7% of EXPECT infants and 15.8% in the QECC. There was no evidence of an increased risk of major congenital anomalies among pregnant women exposed to omalizumab compared with a disease-matched unexposed cohort. Given the observational nature of this registry, however,an absence of increased risk with omalizumab cannot be definitively established.

Long-term effects of prenatal exposure to earthquake on adult schizophrenia.

Maternal exposure to major stressors during pregnancy has been found to increase the risk of neurodevelopmental, cognitive and psychiatric disorders in the offspring. However, the association between prenatal exposure to earthquake and the risk of adult schizophrenia has yet to be examined. To explore the potential long-term effects of prenatal exposure to maternal stress on the risk of schizophrenia in adulthood, using the Great Tangshan Earthquake in 1976 as a natural experiment. We obtained data from the Second China National Sample Survey on Disability, and analysed 94 410 Chinese individuals born between 1975 and 1979. We obtained difference-in-differences estimates of the earthquake effects on schizophrenia by exploiting temporal variation in the timing of earthquake exposure across four birth cohorts born between 1975 and 1979, along with geographical variation in earthquake severity at the prefecture level. Schizophrenia was ascertained by psychiatrists using the ICD-10 classification. Earthquake severity was measured by seismic intensity. Earthquake cohort who experienced prenatal exposure to felt earthquake had higher risk of schizophrenia (odds ratio, 3.38; 95% CI 1.43-8.00) compared with the unexposed reference cohort. After specifying the timing of exposure by the trimester of pregnancy, prenatal exposure to felt earthquake during the first trimester of pregnancy increased the risk of adulthood schizophrenia significantly (odds ratio, 7.45; 95% CI 2.83-19.59). Prenatal (particularly early pregnancy) exposure to maternal stress after a major disaster substantially affects the mental health of Chinese adults.

Type of Delivery, Neuropsychological Development and Intelligence in Twin Births.

Based on a retrospective cohort design with 6-year-old children born in twin births, the relationship between verbal, non-verbal, global neuropsychological development, general intelligence and type of delivery has been studied. To this end, the possible effect of third gestational, obstetric and neonatal variables, such as maternal age at delivery, fetal presentation, gestational age, newborn weight and Apgar at minute one, was controlled. The exposed cohort includes children born by cesarean section, and the unexposed cohort is composed of children born vaginally with or without induction. A total of 124 children were evaluated in their 1st year of primary school using the Child Neuropsychological Maturity Questionnaire, Kaufman’s Intelligence Test and the medical histories of the children collected after birth. By means of binary logistic regression analysis, it has been found that the type of delivery is presented as an independent risk factor for disorders in verbal, non-verbal and global development and for the general intellectual difficulties of children born of multiple births. These results suggest the need to analyze in future prospective studies with broader samples the relationship between different types of obstetric and perinatal variables of birth type and infant neuropsychological development and general intelligence, in order to prevent possible psychological alterations from birth.

Is There an Increased Risk of Criminal Behavior Among Children Who Were In Utero When Their Mothers Were Exposed to Increased Alcohol Availability? A Register-Based Study Using a Natural Experiment Setting

Increased alcohol availability influences drinking behavior; however, little is known about the effect of availability changes on subsequent generations. This study examined whether exposure to increased alcohol availability while pregnant is associated with criminal behavior in subsequent generations. A register-linked study was conducted using data from a natural experiment setting, including 363,207 children born between 1965 and 1971. During 1967/68, strong beer became temporarily available in grocery stores instead of state-owned monopoly stores only, for individuals less than 21 years of age, in two regions of Sweden. Children born in regions exposed to the policy change were compared with children born elsewhere in Sweden (excluding a border area), children born before 1967, and children conceived after 1968. Information on criminal outcomes was obtained from the National Register of Criminal Convictions. Follow-up was from age 15 to 42 years. Hazard ratios with 95% confidence intervals were estimated using Cox regression analysis. Compared with the unexposed cohorts, children conceived by young mothers before the policy change but exposed to the change in utero did not appear to be at an increased risk of being convicted of a violent crime, theft, or drunk driving later in life. Similar patterns of results were found among children conceived by older mothers. Using data from a natural experiment setting, no consistent evidence was found that being exposed to increased alcohol availability while pregnant increased the risk of having a child who would be convicted of a crime later in life.

Gone in 60 seconds: Sub-lethal Effects of Metofluthrin Vapors on Behavior and Fitness of Resistant and Field Strains of Aedes aegypti (Diptera: Culicidae).

Spatial repellents can reduce fecundity and interrupt oviposition behavior in Aedes aegypti. Yet, it is unclear if short exposure times, resistant phenotypes, and other aspects of spatial repellents can impact these effects on mosquito reproduction. To address these issues, pyrethroid susceptible, pyrethroid resistant, and field strains of Ae. aegypti were used to evaluate the extent to which fecundity and oviposition behavior are affected following metofluthrin exposure. Mosquitoes were exposed for 60 s to a sub-lethal dose (LC30) of metofluthrin before blood feeding and allowed 72 h to become gravid before evaluation in an oviposition bioassay for an additional 72 h. Metofluthrin-exposed susceptible, field, and to a lesser extent resistant strain Ae. aegypti showed oviposition across fewer containers, less egg yield, less egg viability, and reduced larval survivorship in hatched eggs compared to unexposed cohorts. Susceptible mosquitoes retained some eggs at dissection following bioassays, and in one case, melanized eggs retained in the female. Treated resistant and field strain F1 larvae hatched significantly earlier than unexposed cohorts and resulted in increased larval mortality in the first 3 d after oviposition. Upon laying, the treated field strain had incompletely melanized eggs mixed in with viable eggs. The treated field strain also had the lowest survivorship of larvae reared from bioassay eggs. These results indicate that metofluthrin could succeed in reducing mosquito populations via multiple mechanisms besides acute lethality. With the available safety data, pre-existing spatial repellent registration, and possibilities for other outdoor delivery methods, metofluthrin is a strong candidate for transition into broader mosquito abatement operations.

Swedish national population-based study shows an increased risk of depression among patients with Hirschsprung disease.

Hirschsprung disease is usually treated during infancy. The long-term impact on mental health has not been well studied. The aim of this study was to assess the risk for depressive disorders in individuals with Hirschsprung disease. This was a nationwide, population-based cohort study. The study exposure was Hirschsprung disease and the study outcome was depression. The exposed cohort included all individuals with Hirschsprung disease, registered in the Swedish National Patient Register between 1964 and 2013 and the unexposed cohort included ten age- and sex-matched controls per patient. The diagnosis of depression was confirmed by diagnosis in the Swedish National Patient Register. The cohort included 739 (76.5% males) individuals with Hirschsprung disease and 7390 (76.5% males) controls. Among the patients with Hirschsprung disease, 35 (4.7%) of the patients had had a depressive disorder and 187 (2.5%) of controls, hazard ratio 1.98, 95% confidence interval 1.38-2.84. The mean age at diagnosis of first depression was 21.9years (SD±7) in Hirschsprung disease patients and 23.4years (SD±7), p=0.236 in the unexposed group. There were no significant gender differences. We found an increased risk of having depressive disorders among individuals with Hirschsprung disease compared to controls.

Clinical impact of intraoperative electronic health record downtime on surgical patients.

Despite increased use of electronic health records (EHRs), the clinical impact of system downtime is unknown. This retrospective matched cohort study evaluated the impact of EHR downtime episodes lasting more than 60 minutes over a 6-year study period. Patients age 18 years or older who underwent surgical procedures at least 60 minutes in duration with an inpatient stay exceeding 24 hours within the study period were eligible for inclusion. Out of 4115 patients exposed to 1 of 176 EHR downtime episodes, 4103 patients were matched to an unexposed cohort in a 1:1 ratio. Multivariable regression analysis, as well as trend analysis for effect of duration of downtime on outcomes, was performed. Downtime-exposed patients had operating room duration 1.1 times longer (p < .001) and postoperative length of stay 1.04 times longer (p = .007) compared to unexposed patients. The 30-day mortality rates were similar between these groups (odds ratio 1.26, p > .05). In trend analysis, there was no association between duration of downtime with respect to evaluated outcomes, postoperative length of stay, and 30-day mortality. EHR downtime had no impact on 30-day mortality. Potential associations for increased postoperative length of stay and duration of time spent in the operating room were observed among downtime-exposed patients. No trend effect was observed with respect to duration of downtime and postoperative length of stay and 30-day mortality rates.

Risk of Incident Obstructive Sleep Apnea Among Patients With Type 2 Diabetes.

This study compared the incidence of obstructive sleep apnea (OSA) in patients with and without type 2 diabetes and investigated risk factors for OSA in patients with type 2 diabetes. A retrospective cohort study was performed to compare OSA incidence between adult patients with and without type 2 diabetes matched for age, sex, and BMI. Patients with a prevalent OSA diagnosis were excluded. The study cohort was derived from The Health Improvement Network (THIN), a U.K. primary care database, from 1 January 2005 to 31 December 2017. There were 3,110 (0.88%) and 5,968 (0.46%) incident OSA cases identified in the 360,250 exposed and 1,296,489 unexposed patient cohorts, respectively. Adjusted incidence rate ratio (aIRR) of OSA in patients with type 2 diabetes compared with those without was 1.48 (95% CI 1.42-1.55; P < 0.001). In a multivariate regression analysis of patients with type 2 diabetes, significant predictors of OSA were diabetes-related foot disease (1.23 [1.06-1.42]; P = 0.005), being prescribed insulin in the last 60 days (1.58 [1.42-1.75]; P < 0.001), male sex (2.27 [2.09-2.46]; P < 0.001), being overweight (2.02 [1.54-2.64]; P < 0.001) or obese (8.29 [6.42-10.69]; P < 0.001), heart failure (1.41 [1.18-1.70]; P < 0.001), ischemic heart disease (1.22 [1.11-1.34]; P < 0.001), atrial fibrillation (1.23 [1.04-1.46]; P = 0.015), hypertension (1.32 [1.23-1.43]; P < 0.001), and depression (1.75 [1.61-1.91]; P < 0.001). When considered alongside previous evidence, this study indicates that the association between type 2 diabetes and OSA is bidirectional. In addition to known predictors of OSA, diabetes-related foot disease and insulin treatment were identified as risk factors in patients with type 2 diabetes.

Comparativa entre 2 técnicas de insuflación laparoscópica cerrada con aguja de Veress. Estudio prospectivo multicéntrico de 300 casos

ObjectiveTo demonstrate that the laparoscopic access technique at Palmer's point at elevated pressures does not cause significant anaesthetic adverse effects in healthy patients, and is also useful for reducing the risk of major injuries compared to the classic umbilical insufflation technique at standard pressures. Material and methodsProspective observational analytical study of cohorts. The cohort exposed to the studied factor consisted of 150 patients undergoing gynaecological laparoscopic surgery in which insufflation with Veress needle in Palmeŕs point until high pressures of 20-25mmHg (Group 1) has been used for access manoeuvres into the abdominal cavity. The unexposed cohort consisted of 150 patients in whom the classical technique of insufflation has been used for access manoeuvres to the abdominal cavity, with the needle at umbilical level up to standard pressures of 12-14mmHg (Group 2). ResultsThe percentage of complications in Group 1 was 5.3%, whereas it was 6.7% in Group 2 (p=0.62). On the other hand, the percentage of technique changes/access location and conversion to laparotomy due to adverse effects during insufflation/entry manoeuvres was 2% and 0% in Group 1, and 2.7% and 2% in Group 2, respectively. ConclusionPalmer's point insufflation at elevated pressures has advantages compared to the classical umbilical technique, as regards the prevention of complications during laparoscopic access manoeuvres.

Comparison of the racing performance of Thoroughbreds with versus without osteochondral fragmentation of the accessory carpal bone identified on yearling sales repository radiographs.

OBJECTIVE To evaluate 2- and 3-year-old and career race performance of Thoroughbred racehorse prospects with and without osteochondral fragmentation of the accessory carpal bone (ACB) identified on yearling presale radiographs. DESIGN Retrospective, matched cohort study. ANIMALS 47 nonlame Thoroughbreds with (exposed cohort) and 94 nonlame Thoroughbreds without (unexposed cohort) osteochondral fragmentation of ACB facture identified on yearling sales repository radiographs. PROCEDURES Repository radiographic interpretation reports for September yearling sales of a large Kentucky auction house from 2005 through 2012 were reviewed, and race records were collected and analyzed. Race performance was compared between horses with and without ACB fracture chosen from the same sale to identify associations between racing performance and ACB fracture. RESULTS No significant differences were identified between horses with or without ACB fracture in their incidence of starting a race as a 2- or 3-year-old and the number of races started, earnings, or earnings per start for 2- or 3-year-old or career race performance. There was no significant difference in performance between horses with or without concurrent carpal osteoarthritis, nor did performance differ between horses with ACB fracture alone and those with ACB fracture and other radiographic abnormalities found to be associated with poorer performance in previous studies. CONCLUSIONS AND CLINICAL RELEVANCE ACB fracture with or without carpal osteoarthritic changes identified on repository radiographs of Thoroughbred yearlings was not associated with poorer racing performance or lower likelihood of starting a race as a 2- or 3-year-old, compared with outcomes for unaffected horses.

Pinworm infections associated with risk of psychiatric disorders-A nationwide cohort study in Taiwan: Pinworm infections and psychiatric disorders

AimThis study aimed to investigate the association between males with pinworm infections and the risk of developing psychiatric disorders. MethodA total of 2044 enrolled patients, with 511 pinworm subjects and 1533 unexposed subjects (1:3) matched for sex, age and index year, from Taiwan's Longitudinal Health Insurance Database (LHID) from 2000 to 2015, selected from the National Health Insurance Research Database (NHIRD). After adjusting for confounding factors, the Cox regression model was used to compare the risk of developing psychiatric disorders during the 15 years of follow-up. ResultsOf all the enrollees, 24 in the pinworm cohort and 18 in the unexposed cohort (343.10 vs 84.96 per 100,000 person-year) developed psychiatric disorders. The Cox regression model revealed that, after adjusting for sex, age, monthly income, urbanization level, geographic region, and comorbidities, the adjusted HR was 4.581 (95% CI: 2.214–9.480, p < .001, p < .001). Pinworm infections were associated with the increased risk in anxiety disorders, depressive disorders, and sleep disorders, respectively. ConclusionPatients who suffered from pinworm infections have a higher risk of developing psychiatric disorders, and this finding should be considered as a timely reminder for the clinicians to provide much more attention for these patients because of their mental health issues.

Hypoglycaemia is associated with increased risk of fractures in patients with type 2 diabetes mellitus: a cohort study.

Objective Type 2 diabetes is associated with an increased risk of fracture. Any factor that incrementally increases this risk should be taken into account when individualising treatment. Hypoglycaemia is a common complication of antidiabetes medications and suggested as a risk factor for fractures; yet, its real-life clinical impact is unclear. Design A population-based, retrospective open cohort study using routinely collected data between 1st of January 1995 and 1st of May 2016 in The Health Improvement Network (THIN) database. Methods Patients with type 2 diabetes mellitus with documented hypoglycaemic events were compared to randomly matched patients with type 2 diabetes mellitus without documented hypoglycaemic events matched to exposed patients on age, sex, duration of diabetes and BMI. The primary outcome was any incident fracture. Secondary outcome was incident fragility (osteoporotic) fracture. Results A total of 41 163 patients with type 2 diabetes were included: 14 147 patients in the exposed cohort and 27 016 patients in the unexposed cohort. Patients with a documented hypoglycaemic event were significantly more likely to sustain any fracture compared to patients with no record of hypoglycaemic events: adjusted IRR = 1.20 (95% CI: 1.12-1.30; P < 0.0001). Patients who had a documented hypoglycaemic event were significantly more likely to suffer a fragility fracture compared to controls: adjusted IRR = 1.24 (95% CI: 1.13-1.37; P < 0.0001). Conclusions Hypoglycaemic events are a significant risk factor for fractures in patients with diabetes mellitus. This observation is clinically relevant when individualising targets for glycaemic control and selecting antidiabetic agents.

Relación entre síndrome de disfunción temporomandibular y síndrome de latigazo cervical tras un accidente de tráfico. Estudio de cohortes

IntroductionWhiplash is a frequent condition in rehabilitation centres, and according to the literature there is a great controversy about its relationship with temporomandibular disorders (TD). The objective of this study is to determine whether there is a higher incidence of TD in patients diagnosed with whiplash during the first 3 and 12 months after having suffered a vehicle accident, and to determine associated risk factors. Patients and methodProspective cohort study conducted between February 2013 to December 2015 with a cohort of 71 adults (36 men and 35 women) that had suffered a Quebec Task Force whiplash grade I or II, together with an unexposed cohort of 70 adults (46 men and 24 women). They were evaluated at 3 and 12 months using the Fonseca's Simplified Anamnestic Index (IASF) ResultsThe results obtained at 3 months showed that the proportion of TD in the exposed cohort was statistically higher than in the non-exposed cohort (53.0% versus 13.4%, P<.0001). At 12 months, the results showed that the proportion of SDT was statistically higher in the exposed cohort than in the non-exposed cohort (53.2% versus 21.7%, P<.0005). ConclusionsAfter a whiplash there is a greater probability of developing a TD. In addition, in the exposed cohort there is a greater deterioration over time in the IASF. The back pain and paraesthesias after a whiplash are symptoms to be taken into account, as they show a statistically significant probability of developing TD.

When It Rains It Pours: The Long-Run Economic Impacts of Salt Iodization in the United States

In 1924, the Morton Salt Company began nationwide distribution of iodine-fortified salt. Access to iodine, a key determinant of cognitive ability, rose sharply. We compare outcomes for cohorts exposed in utero with those of slightly older, unexposed cohorts, across states with high versus low baseline iodine deficiency. Income increased by 11%, labor force participation rose 0.68 percentage points, and full-time work went up 0.9 percentage points due to increased iodine availability. These impacts were largely driven by changes in the economic outcomes of young women. In later adulthood, both men and women had higher family incomes due to iodization.

The effects of in utero exposure to the 1918 influenza pandemic on family formation

A growing literature ties in utero conditions to life course outcomes, including education, earnings, and adult health and mortality. A smaller literature has begun to examine the intergenerational impacts of in utero conditions. A link between these two literatures—the impacts of in utero conditions on family formation—has had few examinations but offers a potential set of mechanisms for the intergenerational reach of early conditions. This paper draws from the 1960 US Decennial Census to examine whether individuals exposed in utero to the 1918/19 influenza pandemic had different family formation patterns than adjacent unexposed cohorts. The findings suggest small overall effects on marriage rates, number of children, and several measures of “type” of spouse for men, but moderate effects for women. For example, women with in utero exposure during their first trimester marry men with 0.2 fewer years of schooling than those not exposed. The findings show that exposed individuals have spouses with lower schooling than unexposed counterparts, this effect is particularly large for women, and it increases the likelihood of marrying spouses with very low levels of schooling.

Abstract P-497: EFFECT OF KETOROLAC ON POST-OPERATIVE CARE OF INFANTS WITH VENTRICULAR SEPTAL DEFECTS AND ATRIOVENTRICULAR CANAL DEFECTS

Aims & Objectives: Intravenous Ketorolac is used for pediatric post-operative care due to its anti-inflammatory and analgesic properties, as well as the potential to decrease need for opioids. Minimal data exists regarding its use in infants under six months, yet our institution frequently uses Ketorolac post-cardiovascular surgery. We sought to investigate whether the use of ketorolac can have clinical benefit in comparison with opioids. Methods We conducted a retrospective chart review of patients under six months of age admitted post-operatively for ventricular septal defect (VSD) and/or atrioventricular canal (AVC) repair between January 2013-September 2017. Outcomes including opiate dose, length of stay (LOS), time to full enteral feeds, and ventilator days were compared between subjects exposed to ketorolac and an unexposed control group. Results Thirty-one children were included, of whom 55% (n=17) received at least one dose of Ketorolac (median total ketorolac dose 4 mg/kg (25–75% IQR 3–5 mg/kg)). Comparing patient characteristics and outcomes between the Ketorolac exposed and unexposed cohorts, there were no differences in age, gender, duration mechanical ventilation, time to full enteral nutrition, or ICU LOS. Most (94%) children received at least one dose of opioid. Opioid duration and total morphine equivalents (per kg) received was not decreased in the Ketorolac cohort (median 0.6 (25–75% IQR 0.4–1.7) vs 0.9 (25–75% IQR 0.4–4.0); p=0.55). Total opioid dose correlated with ICU LOS (r2=0.15; p=0.03), but total Ketorolac dose did not. Conclusions In this small cohort, Ketorolac use was not associated with a reduction in opioid exposure or differences in clinical outcomes.

Risk of Hyperglycemia and Diabetes after Early-Life Famine Exposure: A Cross-Sectional Survey in Northeastern China

Previous studies suggested that malnutrition during early life may play an essential role in later outcomes and disease risk in adulthood. We aimed to investigate the risks of hyperglycemia and diabetes 50 years after early-life famine exposure in a Northeastern Chinese population. We used the data from 5690 adults born between 1956 and 1965 in selected communities from a 2012 cross-sectional study. The early-childhood exposure cohort showed an increased risk of hyperglycemia compared with the unexposed cohort in the female population (odds ratio (OR) 1.46; 95% confidence interval (CI) 1.04, 2.06). The increased risk of diabetes in the early-childhood and fetal exposure cohorts was 37.0% (95% CI 1.05–1.79) and 50% (95% CI 1.15–1.96), respectively. For women, the risk of diabetes was more pronounced in the fetal-exposed cohort (OR 1.82; 95% CI 1.26–2.63) than in the early-childhood cohort (OR 1.57; 95% CI 1.08–2.26). Early-life exposure to famine increased the risk of diabetes. Furthermore, early-childhood exposure to famine might increase the risk of hyperglycemia in women. A policy for preventing early life malnutrition should be drafted by the government to prevent hyperglycemia and diabetes in adulthood.

Autoimmune antibodies and asbestos exposure: Evidence from Wittenoom, Western Australia.

Studies comparing different forms of asbestos are rare, and limited by the failure to compare results with unexposed populations. We compare autoimmune responses among former workers and residents of the crocidolite mining and milling town of Wittenoom, Western Australia, with an unexposed population. ANA testing using indirect immunofluorescence was performed on randomly selected serum samples from Wittenoom workers or residents and compared with those from participants of another unexposed cohort study. ANA scores were higher in the Wittenoom participants compared with Busselton and the odds of being ANA positive was fivefold greater among Wittenoom participants than Busselton (OR 5.5, 95%CI 2.3-13.0). This study is the first to report increased ANA positivity among persons exposed exclusively to crocidolite. This finding of a high frequency of positive ANA tests among crocidolite-exposed subjects may be an indicator for an increased risk of systemic autoimmune diseases and needs further scrutiny.

Risk of infection following semi-invasive ultrasound procedures in Scotland, 2010 to 2016: A retrospective cohort study using linked national datasets.

Outbreak reports indicate a risk of cross-infection following medical procedures using semi-invasive ultrasound probes. This study aimed to evaluate the risk of infection, using microbiological reports and antibiotic prescriptions as proxy measures, associated with semi-invasive ultrasound probe procedures, including transoesophageal echocardiography, transvaginal and transrectal ultrasound. Patient records from the Electronic Communication of Surveillance in Scotland and the Prescribing Information System were linked with the Scottish Morbidity Records for cases in Scotland between 2010 and 2016. Three retrospective cohorts were created to include inpatients/day-cases and outpatients in the following specialties: Cardiology, Gynaecology and Urology. Cox regression was used to quantify the association between semi-invasive ultrasound probe procedures and the risk of positive microbiological reports and community antibiotic prescriptions in the 30-day period following the procedure. There was a greater hazard ratio of microbiological reports for patients who had undergone transoesophageal echocardiography (HR: 4.92; 95% CI: 3.17-7.63), transvaginal (HR: 1.41; 95% CI: 1.21-1.64) and transrectal ultrasound (HR: 3.40; 95% CI: 2.90-3.99), compared with unexposed cohort members after adjustment for age, co-morbidities, previous hospital admissions and past care home residence. Similarly, there was a greater hazard ratio of antibiotic prescribing for those who had received transvaginal (HR: 1.26; 95% CI: 1.20-1.32) and transrectal (HR: 1.75; 95% CI: 1.66-1.84) ultrasound, compared with unexposed patients. Analysis of linked national datasets demonstrated a greater risk of infection within 30 days of undergoing semi-invasive ultrasound probe procedures, using microbiological reports and antibiotic prescriptions as proxy measures of infection.

Risk of early‐onset breast cancer among women exposed to thoracic computed tomography in pregnancy or early postpartum

Background The risk of breast cancer may be higher with direct exposure to ionizing radiation from thoracic computed tomography (CT) during pregnancy or the postpartum. We evaluated the short-term risk of maternal breast cancer after exposure to thoracic CT during these periods. Methods We completed a retrospective population-based cohort study of all deliveries between 1995 and 2014 using universal healthcare databases in the province of Ontario, Canada. The main exposure was thoracic CT in pregnancy or ≤42days postpartum. The passive exposure was ventilation-perfusion scintigraphy (VQ) scan in pregnancy or ≤42 days postpartum. Each was compared to pregnancies unexposed to thoracic CT or VQ scan. The primary study outcome was newly diagnosed breast cancer starting 366days post-index delivery date. Results A total of 5859 pregnancies were exposed to thoracic CT, 4075 to VQ scan and 1292059 to neither. Starting from 1year after the index delivery, the median duration of follow-up was 5.9, 7.3 and 11.1years, respectively. A total of 10129 women were diagnosed with breast cancer, of whom 9039 (89.2%) were aged ≤50years. There were 27 new cases of breast cancer (7.1 per 10000 person-years) following thoracic CT vs. 10080 (7.0 per 10000 person-years) among the unexposed, an adjusted hazard ratio (HR) of 1.17 (95% confidence interval [CI], 0.80-1.70). Following VQ scan exposure, the incidence rate of breast cancer was 7.0 per 10000 person-years, an adjusted HR of 1.23 (95% CI 0.81-1.87), compared with the unexposed cohort. Conclusion Exposure to thoracic CT during pregnancy or the postpartum was not associated with an increased short-term risk of maternal breast cancer. The long-term risk should be studied.