# The emergence of common health conditions across the life course: evidence from the Born in Bradford family cohort

## TL;DR

A study of nearly 10,000 mothers in Bradford found that South Asian women had higher rates of diabetes and liver disease but lower rates of cancer and mental health disorders compared to White European women.

## Contribution

The study provides new evidence on ethnic differences in the incidence of 21 health conditions using longitudinal health records from a large family cohort.

## Key findings

- South Asian women had higher incidence of diabetes, chronic liver disease, and thyroid disorders compared to White European women.
- South Asian women had lower incidence of cancer, mental health disorders, and neuromuscular conditions compared to White European women.
- Differences in health conditions may be influenced by social, cultural, lifestyle, environmental, and genetic factors.

## Abstract

Born in Bradford (BiB) is a family cohort study with linked routine health records. We calculated the rates of common health conditions and explored differences between White European and South Asian participants.

21 health conditions were identified using diagnostic codes and prescription records extracted from electronic health records. Period prevalence of each condition was calculated for the two years before recruitment, and incidence rates per 1000 person years were calculated from recruitment to BiB to the end of 2021, or earlier if censored. Age-adjusted Cox proportional hazard models were used to estimate hazard ratios (HR) between ethnic groups.

The sample included 9,784 mothers, 52% of whom were of South Asian heritage and 48% were White European. The highest prevalence and incidence rates were observed for common mental health disorders and eczema. We found evidence that South Asian women had higher incidence of 14/21 conditions, including diabetes (HR 3.94 [95% CI 3.15, 4.94]), chronic liver disease (2.98 [2.29, 3.88]) and thyroid disorders (1.87 [1.50, 2.33]), and had lower incidence of cancer (0.51 [0.38, 0.68]), other and common mental health disorders (0.56 [0.45, 0.71] and 0.69 [0.64, 0.74] respectively), and other neuromuscular conditions (0.63 [0.49, 0.82]).

We report differences in several non-communicable health conditions between White European and South Asian women. The higher rates of some health conditions observed in South Asian participants may be explained by social, cultural, lifestyle, environmental, and genetic factors and highlights the importance of understanding and addressing these factors to reduce health inequalities. It is already known that the risk of some diseases, e.g., diabetes, is associated with South Asian ethnicity and these results reinforce the need for culturally appropriate public health interventions to address modifiable risk factors at both an individual and systems level to reduce the burden of long-term health conditions.

Born in Bradford is a research study which aims to find out what keeps families healthy by tracking the lives of over 40,000 people living in Bradford, which is a city in the north of England. We looked at the medical history of nearly 10,000 mothers taking part in the study to see how many had developed one or more of 21 health conditions since they joined the study. We found that women of South Asian heritage were more likely to develop diabetes, chronic liver disease, and thyroid disorders compared to white women, but were less likely to develop cancer, common mental health disorders and neuromuscular conditions such as fibromyalgia. These differences may be explained by social, cultural, lifestyle, environmental and genetic factors, and it is important to understand why this happens. By doing so, we can try to address potential risk factors for these diseases to reduce health inequalities and prevent people from living with long-term health conditions.