Egocentric social network characteristics and cardiovascular risk among patients with hypertension or diabetes in western Kenya: a cross-sectional analysis from the BIGPIC trial

Abstract

Objectives: Management of cardiovascular disease (CVD) is an urgent challenge in low-income and middle-income countries, and interventions may require appraisal of patients' social networks to guide implementation. The purpose of this study is to determine whether egocentric social network characteristics (SNCs) of patients with chronic disease in western Kenya are associated with overall CVD risk and individual CVD risk factors.

Design: Cross-sectional analysis of enrollment data (2017-2018) from the Bridging Income Generation with GrouP Integrated Care trial. Non-overlapping trust-only, health advice-only and multiplex (trust and health advice) egocentric social networks were elicited for each participant, and SNCs representing social cohesion were calculated.

Setting: 24 communities across four counties in western Kenya.

Participants: Participants (n=2890) were ≥35 years old with diabetes (fasting glucose ≥7 mmol/L) or hypertension.

Primary and secondary outcomes: We hypothesised that SNCs would be associated with CVD risk status (QRISK3 score). Secondary outcomes were individual CVD risk factors.

Results: Among the 2890 participants, 2020 (70%) were women, and mean (SD) age was 60.7 (12.1) years. Forty-four per cent of participants had elevated QRISK3 score (≥10%). No relationship was observed between QRISK3 level and SNCs. In unadjusted comparisons, participants with any individuals in their trust network were more likely to report a good than a poor diet (41% vs 21%). SNCs for the trust and multiplex networks accounted for a substantial fraction of variation in measures of dietary quality and physical activity (statistically significant via likelihood ratio test, adjusted for false discovery rate).

Conclusion: SNCs indicative of social cohesion appear to be associated with individual behavioural CVD risk factors, although not with overall CVD risk score. Understanding how SNCs of patients with chronic diseases relate to modifiable CVD risk factors could help inform network-based interventions.

Trial registration number: ClinicalTrials.gov identifier: NCT02501746; https://ichgcp.net/clinical-trials-registry/NCT02501746.

Keywords: cardiology; epidemiology; hypertension; public health.

Conflict of interest statement

Competing interests: None declared.

© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.

Figures

Figure 1

Example of an egocentric network. This example participant responds to the social network survey saying she discusses ‘important matters’ with alter A and ‘health matters with alters A, B and C. Because the participant discusses both ‘important’ and ‘health matters’ with alter A, alter A is in the multiplex (trust and advice) network, leaving just alters B and C in the advice-only network and no alters in the trust-only network.

Figure 2

Distribution of CVD risk status and behavioural CVD risk factors (diet and physical activity) by network and degree. Bars illustrate the distribution of CVD risk status and behavioural risk factors for trust, advice and multiplex networks by network degree (no alters, one alter or two or more alters). (A) CVD risk status (elevated CVD: QRISK≥10%), by network and degree. (B) Diet, by network and degree. (C) Physical activity, by network and degree. CVD, cardiovascular disease.

Figure 3

Results of likelihood ratio hypothesis tests for effect of social network characteristics on CVD risk factor outcomes, with multiple comparisons threshold indicated by vertical line. Owing to the compressed scale for p-values, we translated p-values to associated Z-scores to enable visible display of all models. Large negative Z-score deviations from zero correspond to smaller p-values for each comparison (online supplemental table S1). For example, a Z-score of 0 corresponds to a p-value of 0.5; a Z-score of −1.96 corresponds to p=0.025. The dashed vertical line at Z = −5 is the threshold for statistical significance after adjusting for multiple comparisons; points to the left of that line represent statistically significant comparisons. Colour indicates type of social network SNCs added (red: trust network, blue: advice network, green: multiplex network). The plot shows that trust networks have an impact on diet, and that multiplex networks have an impact on physical activity. BMI, body mass index; CVD, cardiovascular disease; LDL, low density lipoprotein; SNC, social network characteristic.