Evaluating the gap in rapid diagnostic testing: insights from subnational Kenyan routine health data

Abstract

Background: Understanding diagnostic capacities is essential to addressing healthcare provision and inequity, particularly in low-income and middle-income countries. This study used routine data to assess trends in rapid diagnostic test (RDT) reporting, supplies and unmet needs across national and 47 subnational (county) levels in Kenya.

Methods: We extracted facility-level RDT data for 19 tests (2018-2020) from the Kenya District Health Information System, linked to 13 373 geocoded facilities. Data quality was assessed for reporting completeness (ratio of reports received against those expected), reporting patterns and outliers. Supply assessment covered 12 RDTs reported by at least 50% of the reporting facilities (n=5251), with missing values imputed considering reporting trends. Supply was computed by aggregating the number of tests reported per facility. Due to data limitations, demand was indirectly estimated using healthcare-seeking rates (HIV, malaria) and using population data for venereal disease research laboratory test (VDRL), with unmet need computed as the difference between supply and demand.

Results: Reporting completeness was under 40% across all counties, with RDT-specific reporting ranging from 9.6% to 89.6%. Malaria RDTs showed the highest annual test volumes (6.3-8.0 million) while rheumatoid factor was the lowest (0.5-0.7 million). Demand for RDTs varied from 2.5 to 11.5 million tests, with unmet needs between 1.2 and 3.5 million. Notably, malaria testing and unmet needs were highest in Turkana County, as well as the western and coastal regions. HIV testing was concentrated in the western and central regions, with decreasing unmet needs from 2018 to 2020. VDRL testing showed high volumes and unmet needs in Nairobi and select counties, with minimal yearly variation.

Conclusion: RDTs are crucial in enhancing diagnostic accessibility, yet their utilisation varies significantly by region. These findings underscore the need for targeted interventions to close testing gaps and improve data reporting completeness. Addressing these disparities is vital for equitably enhancing diagnostic services nationwide.

Keywords: EPIDEMIOLOGY; Health Services Accessibility; PUBLIC HEALTH.

Figure 1. Geographical variation in the proportion of reports received from those expected to be submitted across the study period (2018–2020) by level. (A) The proportion of reports received¹ from health facilities (irrespective of RDT) by county out of expected² reports facility reports. (B) The proportion of RDT reports received for a subset of the RDTs considered: HIV, VDRL and malaria RDTs out of expected RDT reports. ¹Received reports refer to MoH 706 reports containing rapid diagnostic data. ²Expected reports refer to the number of monthly reports required to be submitted within a specific timeframe in the DHIS2. Since this study spans 3 years, it means each facility is expected to have submitted 36 reports. DHIS2, District Health Information System; RDT, rapid diagnostic test; VDRL, venereal disease research laboratory; MoH, Ministry of Health.

Figure 2. Proportion of facilities reporting ≥9+ months and <9 months of RDT data per year among those reporting an RDT (shown in table 1). The denominator for each RDT varies annually, as shown in table 1. HB, haemoglobin; HCG, human chorionic gonadotropin; RDT, rapid diagnostic test; CHEW, community health extension worker

Figure 3. (A) Annual supply of 12 RDTs at the national level for facilities that submitted at least one report. (B) Annual supply, demand and unmet needs for three RDTs (HIV, total Malaria RDTs and VDRL) only due to data limitations. *Supply restricted to 10 CHEW counties in western Kenya. **Total Malaria RDT computed as the sum of CHEW Malaria RDTs and facility Malaria RDTs. RDTs, rapid diagnostic tests; VDRL, venereal disease research laboratory; CHEW, community health extension worker.

Figure 4. Geographical variation in supply, demand and unmet needs for (A) VDRL, (B) HIV, and (C) Total malaria RDTs per year among all reporting facilities. RDTs, rapid diagnostic tests; VDRL, venereal disease research laboratory; HIV, human immunodeficiency virus.