Study design
This study was based on secondary analyses of population-based data from the 2018 Kyrgyzstan Demographic and Health Survey (DHS). The DHS collected data on demographic, environmental, socio-economic, and health issues, including GBV and hypertension. The sample for the 2018 Kyrgyzstan DHS was nationally representative covering the entire population in the country on individual and household levels. The detailed survey design and procedures are found in the 2018 Kyrgyzstan DHS report.
During the DHS survey 6,021 women aged 15–49 years were interviewed in the GBV module of the DHS and 4793 women were screened for hypertension.
Eligibility criteria and sampling
We included all women aged 15–54 years who responded to the GBV DHS questions and whose blood pressure levels were sampled.
Outcome variable
The study’s primary outcome was hypertension. Respondents were deemed to have hypertension if their systolic or diastolic blood pressure was greater than 140 mm Hg or 90 mm Hg, respectively, or if they were currently using an anti-hypertensive medication. According to the respondent’s cuff size, the blood pressure was measured three times at intervals of ten minutes using small, medium, and large cuff sizes. To classify hypertension, the average of the second and third measures was employed [15].
Exposure variable
Using a modified and previously validated version of the Conflict Tactic Scale [16], exposure to GBV/IPV against women (spousal physical, sexual, and emotional abuse) was evaluated. GBV is defined as exposure to one or more of the following situations perpetrated by a husband or partner ever. To determine physical abuse, six factors were considered: whether the abuser ever shoved, shook, or threw something; whether they ever slapped; whether they ever used harmful punches; whether they ever kicked or dragged; whether they ever attempted to strangle or burn; and whether they ever used a knife, gun, or other weapon to threaten the other. Forced sexual contact and other unwanted sexual activities were the two characteristics utilised to quantify sexual abuse. The following three factors were used to gauge emotional abuse: whether or not her partner had ever made her feel bad or embarrassed in front of others, threatened to hurt her, or insulted her [17].
Control variables
The following individual-level factors were included in the study: occupation (working or not working); residential area (urban or rural); Respondents’ age in years, educational attainment (no education, primary, secondary or higher); weight was measured to the nearest 0.5 kg with subjects in light clothing, and height was measured to the nearest 0.1 cm. Body mass index (BMI) was calculated and categorized as underweight (< 18.5 kg/m2), overweight (25–29.9 kg/m2), and obese (≥ 30 kg/m2). DHS wealth index was used as a proxy indicator for the socio-economic position. Thus, wealth status was categorised into poorest, poorer, middle, richer and richest categories [18].
Statistical analysis
In the descriptive statistics, the distribution of respondents by the key variables was expressed as frequencies and percentages. We used Pearson’s chi-squared test to compare participants’ characteristics and hypertension. Multivariate logistic regression analysis was also used to identify the association between GBV and hypertension. Odds ratios (OR) and 95% confidence interval (CI) were calculated to measure the strengths of associations, and a statistical significance was set at the p-value < 0.05. Data analysis was performed using Stata software (Version 17, StataCorp, Texas, USA).