Associations between primary care recorded cannabis use and mental ill health in the UK: a population-based retrospective cohort study using UK primary care data.

BACKGROUND: Cannabis use is a global public health issue associated with increased risks of developing mental health disorders, especially in young people. We aimed to investigate the relationships between cannabis exposure and risks of receiving mental illness diagnoses or treatment as outcomes. METHODS: A population based, retrospective, open cohort study using patients recorded in 'IQVIA medical research data', a UK primary care database. Read codes were used to confirm patients with recorded exposure to cannabis use who were matched up to two unexposed patients. We examined the risk of developing three categories of mental ill health: depression, anxiety or serious mental illness (SMI). RESULTS: At study entry, the exposed cohort had an increased likelihood of having experienced mental ill health [odds ratio (OR) 4.13; 95% confidence interval (CI) 3.99-4.27] and mental ill health-related prescription (OR 2.95; 95% CI 2.86-3.05) compared to the unexposed group. During the study period we found that exposure to cannabis was associated with an increased risk of developing any mental disorder [adjusted hazard ratio (aHR) 2.73; 95% CI 2.59-2.88], also noted when examining by subtype of disorder: anxiety (aHR 2.46; 95% CI 2.29-2.64), depression (aHR 2.34; 95% CI 2.20-2.49) and SMI (aHR 6.41; 95% CI 5.42-7.57). These results remained robust in sensitivity analyses. CONCLUSION: These findings point to the potential need for a public health approach to the management of people misusing cannabis. However, there is a gross under-recording of cannabis use in GP records, as seen by the prevalence of recorded cannabis exposure substantially lower than self-reported survey records.

Postpartum haemorrhage and risk of mental ill health: A population-based longitudinal study using linked primary and secondary care databases.

There is a gap in the literature investigating the impact of obstetric complications on subsequent mental ill health outcomes. The aim of this study was to establish the association between post-partum haemorrhage (PPH) and mental ill health. We conducted a retrospective open cohort study utilizing linked primary care (The Health Improvement Network (THIN)) and English secondary care (Hospital Episode Statistics (HES)) databases, from January 1, 1990 to January 31, 2018. A total of 42,327 women were included: 14,109 of them were exposed to PPH during the study period and 28,218 unexposed controls were matched for age and date of delivery. Hazard ratios (HRs) for mental illness among women with and without exposure to PPH were estimated after controlling for covariates. Women who had had PPH were at an increased risk of developing postnatal depression (adjusted HR: 1·10, 95%CI: 1·01-1·21) and post-traumatic stress disorder (PTSD) (adjusted HR: 1·17, 95%CI: 0·73-1·89) compared to women unexposed to PPH. When restricting the follow-up to the first year after childbirth, the adjusted HR for PTSD was 3·44 (95% CI 1·31-9·03). No increase in the overall risk was observed for other mental illnesses, including depression (adjusted HR: 0·94, 95%CI: 0·87-1·01), severe mental illness (adjusted HR: 0·65, 95%CI: 0·40-1·08, p = 0·239) and anxiety (adjusted HR: 0·99, 95%CI: 0·90-1·09). PPH is associated with a significant increase in the risk of developing postnatal depression and PTSD in the first year after delivery. Active monitoring for mental illness should form an integral part of the follow-up in women who suffered a PPH.

The association between exposure to domestic abuse in women and the development of syndromes indicating central nervous system sensitization: A retrospective cohort study using UK primary care records.

BACKGROUND: Domestic abuse is a global public health issue. The association between the development of central sensitivity syndromes (CSS) and previous exposure to domestic abuse has been poorly understood particularly within European populations. METHODS: A retrospective cohort study using the 'The Health Improvement Network,' (UK primary care medical records) between 1st January 1995-31st December 2018. 22,604 adult women exposed to domestic abuse were age matched to 44,671 unexposed women. The average age at cohort entry was 36 years and the median follow-up was 2.5 years. The outcomes of interest were the development of a variety of syndromes which demonstrate central nervous system sensitization. Fibromyalgia, chronic fatigue syndrome and temporomandibular joint disorder outcomes have been reported previously. Outcomes were adjusted for the presence of mental ill health. RESULTS: During the study period, women exposed to domestic abuse experienced an increased risk of developing chronic lower back pain (adjusted incidence rate ratio [aIRR] 2.28; 95% CI 1.85-2.80), chronic headaches (aIRR 3.15; 95% CI 1.07-9.23), irritable bowel syndrome (aIRR 1.41; 95% CI 1.25-1.60) and restless legs syndrome (aIRR 1.89; 95% CI 1.44-2.48). However, no positive association was seen with the development of interstitial cystitis (aIRR 0.52; 95% CI 0.14-1.93), vulvodynia (aIRR 0.42; 95% CI 0.14-1.25) and myofascial pain syndrome (aIRR 1.01; 95% CI 0.28-3.61). CONCLUSION: This study demonstrates the need to consider a past history of domestic abuse in patients presenting with CSS; and also consider preventative approaches in mitigating the risk of developing CSS following exposure to domestic abuse. SIGNIFICANCE: Domestic abuse is a global public health issue, with a poorly understood relationship with the development of complex pain syndromes. Using a large UK primary care database, we were able to conduct the first global cohort study to explore this further. We found a strong pain morbidity burden associated with domestic abuse, suggesting the need for urgent public health intervention to not only prevent domestic abuse but also the associated negative pain consequences.

Data extraction for epidemiological research (DExtER): a novel tool for automated clinical epidemiology studies.

The use of primary care electronic health records for research is abundant. The benefits gained from utilising such records lies in their size, longitudinal data collection and data quality. However, the use of such data to undertake high quality epidemiological studies, can lead to significant challenges particularly in dealing with misclassification, variation in coding and the significant effort required to pre-process the data in a meaningful format for statistical analysis. In this paper, we describe a methodology to aid with the extraction and processing of such databases, delivered by a novel software programme; the "Data extraction for epidemiological research" (DExtER). The basis of DExtER relies on principles of extract, transform and load processes. The tool initially provides the ability for the healthcare dataset to be extracted, then transformed in a format whereby data is normalised, converted and reformatted. DExtER has a user interface designed to obtain data extracts specific to each research question and observational study design. There are facilities to input the requirements for; eligible study period, definition of exposed and unexposed groups, outcome measures and important baseline covariates. To date the tool has been utilised and validated in a multitude of settings. There have been over 35 peer-reviewed publications using the tool, and DExtER has been implemented as a validated public health surveillance tool for obtaining accurate statistics on epidemiology of key morbidities. Future direction of this work will be the application of the framework to linked as well as international datasets and the development of standardised methods for conducting electronic pre-processing and extraction from datasets for research purposes.

The association between exposure to childhood maltreatment and the subsequent development of functional somatic and visceral pain syndromes.

BACKGROUND: Childhood maltreatment is a global public health issue linked to a vast mortality and morbidity burden. This study builds on current literature to explore the risk of developing central sensitivity syndromes (CSS) (consisting of somatic and visceral pain syndromes) subsequent to childhood maltreatment exposure. METHODS: A retrospective population based open cohort study using the UK primary care database, 'The Health Improvement Network,' between 1st January 1995-31st December 2018. 80,657 adult patients who had experienced childhood maltreatment or maltreatment related concerns (exposed patients) were matched to 161,314 unexposed patients by age and sex. Outcomes of interest were the development of CSS: either somatic (Fibromyalgia, chronic fatigue syndrome, temporomandibular joint disorder, chronic lower back pain, chronic headache, myofascial pain syndrome and restless leg syndrome) or visceral (Interstitial cystitis, vulvodynia, chronic prostatitis and irritable bowel syndrome) in nature. Effect sizes are presented as adjusted incidence rate ratios (aIRR) with confidence intervals (CI). Models were adjusted for the following covariates at cohort entry: age, sex, deprivation, anxiety, depression and serious mental ill health. RESULTS: The average age at cohort entry was 23.4 years and the median follow was 2.2 years. There was an increased risk of developing fibromyalgia (aIRR 2.06; 95% CI 1.71-2.48), chronic fatigue syndrome (1.47; 1.08-2.00), chronic lower back pain (1.99; 1.68-2.35), restless leg syndrome (1.82; 1.41-2.35) and irritable bowel syndrome (1.15; 1.08-1.22) when compared to the unexposed group, whereas no statistical association was seen with the development of temporomandibular joint disorder (1.00; 0.88-1.13), chronic headache (1.04; 0.59-1.86), interstitial cystitis (1.19; 0.51-2.74), vulvodynia (0.65; 0.34-1.26), chronic prostatitis (0.34; 0.07-1.77) and myofascial pain syndrome (0.88; 0.36-2.14). Outcome numbers were low, most likely, due to the rarity of visceral conditions (aside from irritable bowel syndrome). The association between a history of childhood maltreatment and CSS were mainly observed in somatic CSS. INTERPRETATION: The debilitating effects of CSS carry a substantial physical, psychological and economic burden to both the individuals who are diagnosed with them and the health services who serve them. Primary prevention approaches targeting childhood maltreatment as well as secondary preventative approaches should be considered to minimise the associated burden of CSS.

Exploration of trends in the incidence and prevalence of childhood maltreatment and domestic abuse recording in UK primary care: a retrospective cohort study using 'the health improvement network' database.

OBJECTIVES: Describe the epidemiology of childhood maltreatment and domestic abuse (in women). DESIGN: Analysis of longitudinal records between 1 January 1995 to 31 December 2018. SETTING: UK primary care database: 'The Health Improvement Network' (THIN). PARTICIPANTS: 11 831 850 eligible patients from 787 contributing practices. Childhood maltreatment and domestic abuse (women only) were defined as the presence of a recorded Read code. OUTCOME MEASURES: The incidence rate (IR) and prevalence of childhood maltreatment (in children aged 0-18 years) and domestic abuse (in women aged over 18) between 1996 and 2017. An adjusted incidence rate ratio (aIRR) is given to examine the differences in IRs based on sex, ethnicity and deprivation. RESULTS: The age and gender breakdown of THIN has been previously reported to be representative of the UK population, however, there is substantial missing information on deprivation quintiles (<20%) and ethnicity (approximately 50%). The IR (IR 60.1; 95% CI 54.3 to 66.0 per 100 000 child years) and prevalence (416.1; 95% CI 401.3 to 430.9 per 100 000 child population) of childhood maltreatment rose until 2017. The aIRR was greater in patients from the most deprived backgrounds (aIRR 5.14; 95% CI 4.57 to 5.77 compared with least deprived) and from an ethnic minority community (eg, black aIRR 1.25; 1.04 to 1.49 compared with white). When examining domestic abuse in women, in 2017, the IR was 34.5 (31.4 to 37.7) per 100 000 adult years and prevalence 368.7 (358.7 to 378.7) per 100 000 adult population. Similarly, the IR was highest in the lowest socioeconomic class (aIRR 2.30; 2.71 to 3.30) and in ethnic minorities (South Asian aIRR 2.14; 1.92 to 2.39 and black aIRR 1.64; 1.42 to 1.89). CONCLUSION: Despite recent improvements in recording, there is still a substantial under-recording of maltreatment and abuse within UK primary care records, compared with currently existing sources of childhood maltreatment and domestic abuse data. Approaches must be implemented to improve recording and detection of childhood maltreatment and domestic abuse within medical records.

Increased Cardiometabolic and Mortality Risk Following Childhood Maltreatment in the United Kingdom.

Background Childhood maltreatment remains a significant public health issue associated with a number of poor health outcomes. This study explores the association between childhood maltreatment and the subsequent development of cardiometabolic disease and all-cause mortality. Methods and Results Using a UK primary care database between January 1, 1995 and December 31, 2018, we conducted a population-based open retrospective cohort study. We matched 80 657 adult patients with a historic recording of childhood maltreatment or maltreatment-related concerns (exposed group) to 161 314 unexposed patients. Outcomes of interest were the development of cardiovascular disease, hypertension, type 2 diabetes mellitus, and risk of all-cause mortality. During the study period there were 243 new diagnoses of cardiovascular disease (incidence rate 8.3 per 10 000 person-years) in the exposed group compared with 254 in the unexposed group (incidence rate 4.6 per 10 000 person-years). Following adjustment for key covariates, this translated to an adjusted incidence rate ratio of 1.71 (95% CI 1.42-2.06). Additionally, the exposed group had an increased risk of hypertension (adjusted incidence rate ratio 1.42; 95% CI, 1.26-1.59), type 2 diabetes mellitus (adjusted incidence rate ratio 2.13; 95% CI, 1.86-2.45) and all-cause mortality (adjusted incidence rate ratio 1.75; 95% CI, 1.52-2.02) during the study period compared with the unexposed group. Conclusions Considering the high prevalence of exposure to childhood maltreatment, we have demonstrated the substantial associated burden of preventable cardiometabolic disease. There is a clear need to ensure that public health approaches are implemented to prevent the adverse consequences following exposure to childhood maltreatment.