P6371Network characteristics of a hypertension referral system in western kenya

Introduction

The Strengthening Referral Networks for Management of Hypertension Across the Health System (STRENGTHS) trial is creating and testing interventions to improve the effectiveness of referral networks for patients with hypertension in Western Kenya.

Purpose

Network analysis of facility-based healthcare providers was used to understand the existing network of referrals. The ultimate goal was to identify both structural gaps and opportunities for implementation of the planned intervention.

Methods

A network survey was administered to providers who deliver care to patients with hypertension asking individuals to nominate a) individuals to whom, and b) facilities to which they refer patients, both up and down the health system. We analyzed survey data using centrality measures of in-degree and out-degree (number of links each provider received and sent, respectively), as well as fitting a core-periphery (CP) model. A higher CP indicates a strong referral network, while a lower CP indicates a relatively weaker network.

Results

Data were collected from 130 providers across 39 sites within 7 geographically separate network clusters. Each cluster consists of a mix of primary, secondary, and/or tertiary facilities. Compared to a perfect CP referral network model (Correlation Score [CP] = 1.00) and a random referral network model (CP = 0.200), the provider referral networks within each cluster showed a weak tendency for CP structure. There was a large range in CP from 0.334 to 0.639. In contrast, cluster-level facility networks showed a strong tendency for CP structure, with a CP range of 0.857 to 0.949.

Core Periphery Correlation Scores [CP] Network Cluster 1 Cluster 2 Cluster 3 Cluster 4 Cluster 5 Cluster 6 Cluster 7 Provider Referrals 0.433 0.424 0.334 0.639 0.535 0.448 0.407 Facility Referrals 0.949 0.894 0.871 0.949 0.949 0.904 0.857 Each cluster represents a geographically separate referral network. A random referral network would reveal a CP score of 0.200; while a perfect referral network would give a CP of 1.00.

Referral Network Models

Conclusions

The current health system across Western Kenya does not demonstrate a strong network of referrals between providers for patients with hypertension. While facility-to-facility referrals are more in-line with a perfect referral model, there are gaps in communication between the specific providers. These results highlight the need for STRENGTHS to design and test interventions that strengthen provider referral patterns in order to improve blood pressure control and reduce cardiovascular risk.

Acknowledgement/Funding

National Institutes of Health: National Heart Lung and Blood Institute, Doris Duke Charitable Foundation:International Clinical Research Fellowship

Blood pressure and chronic kidney disease progression in a multi-racial cohort: the Multi-Ethnic Study of Atherosclerosis

The relationship between blood pressure (BP) and kidney function among individuals with chronic kidney disease (CKD) remains controversial. This study evaluated the association between BP and estimated glomerular filtration rate (eGFR) decline among adults with nondiabetic stage 3 CKD. The Multi-Ethnic Study of Atherosclerosis participants with an eGFR 30-59  ml min(-1) per 1.73 m2 at baseline without diabetes were included. Participants were followed over a 5-year period. Kidney function change was determined by annualizing the change in eGFR using cystatin C, creatinine and a combined equation. Risk factors for progression of CKD (defined as a decrease in annualized eGFR>2.5 ml min(-1) per 1.73 m2) were identified using univariate analyses and sequential logistic regression models. There were 220 participants with stage 3 CKD at baseline using cystatin C, 483 participants using creatinine and 381 participants using the combined equation. The median (interquartile range) age of the sample was 74 (68-79) years. The incidence of progression of CKD was 16.8% using cystatin C and 8.9% using creatinine (P=0.002). Systolic BP>140 mm Hg or diastolic BP>90 mm Hg was significantly associated with progression using a cystatin C-based (odds ratio (OR), 2.49; 95% confidence interval (CI), 1.12-5.52) or the combined equation (OR, 2.07; 95% CI, 1.16-3.69), but not when using creatinine after adjustment for covariates. In conclusion, with the inclusion of cystatin C in the eGFR assessment hypertension was an important predictor of CKD progression in a multi-ethnic cohort with stage 3 CKD.