1 Chandan JS, et al. BMJ Open 2020;10:e036949. doi:10.1136/bmjopen-2020-036949 Open access 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 Joht Singh Chandan , 1,2 Krishna Margadhamane Gokhale, 2 Caroline Bradbury-Jones, 3 Krishnarajah Nirantharakumar, 2 Siddhartha Bandyopadhyay, 4 Julie Taylor 3,5 To cite: Chandan JS, Gokhale KM, Bradbury-Jones C, et al. 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. BMJ Open 2020;10:e036949. doi:10.1136/ bmjopen-2020-036949 ► Prepublication history and additional material for this paper are available online. To view these fles, please visit the journal online (http://dx.doi. org/10.1136/bmjopen-2020- 036949). KN, SB and JT contributed equally. Received 13 January 2020 Revised 26 March 2020 Accepted 06 May 2020 For numbered affliations see end of article. Correspondence to Dr Joht Singh Chandan; joht.chandan@nhs.net Original research © Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. ABSTRACT 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 defned 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. INTRODUCTION Childhood maltreatment (physical, sexual or emotional abuse and neglect against those under the age of 18 years) 1 and domestic abuse (controlling, coercive, threatening behaviour, violence or abuse between those who are, or have been, intimate partners or family members) 2 are global public health problems. The negative downstream social, psychological and physical health effects of childhood maltreatment and domestic abuse bear a substantial societal cost. 3–12 Therefore, a public health approach is urgently needed to prevent both the occurrence of childhood maltreatment and domestic abuse as well Strengths and limitations of this study ► Primary care data encompass a vast proportion of society, and as current guidance is to ensure iden- tifcation of domestic abuse and childhood mal- treatment by general practitioners, studying the epidemiology within this dataset is important. ► Despite the vast cohort size, our results demonstrate substantial under-recording of childhood maltreat- ment and domestic abuse. ► Although the study was able to examine trends by age, gender, deprivation and ethnicity, trends by ethnicity were limited due to extensive missing data within UK primary care. ► Before primary care data can used as a tool for pub- lic health surveillance of childhood maltreatment and domestic abuse, there is a defnite need for im- proved recording and/or reporting.