Distance as explanatory factor for sexual health centre utilization: an urban population-based study in the Netherlands

Abstract

Background: The central sexual health centre (SHC) in the greater Rotterdam area in the Netherlands helps finding people unaware of their STI/HIV status. We aimed to determine a possible association between SHC utilization and travel distance in this urban and infrastructure-rich area. Insight in area-specific utilization helps adjust outreach policies to enhance STI testing.

Methods: The study population consists of all residents aged 15-45 years in the greater Rotterdam area (2015-17). We linked SHC consultation data from STI tested heterosexual clients to the population registry. The association between SHC utilization and distance was investigated by multilevel modelling, adjusting for sociodemographic and area-specific determinants. The data were also stratified by age (aged < 25 years) and migratory background (non-Western), since SHC triage may affect their utilization. We used straight-line distance between postal code area centroid and SHC address as a proxy for travel distance.

Results: We found large area variation in SHC utilization (range: 1.13-48.76 per 1000 residents). Both individual- and area-level determinants determine utilization. Travel distance explained most area variation and was inversely associated with SHC utilization when adjusted for other sociodemographic and area-specific determinants [odds ratio (OR) per kilometre: 0.95; 95% confidence interval (CI): 0.93-0.96]. Similar results were obtained for residents <25 years (OR: 0.95; 95% CI: 0.94-0.96), but not for non-Western residents (OR: 0.99; 95% CI: 0.99-1.00).

Conclusions: Living further away from a central SHC shows a distance decline effect in utilization. We recommend to enhance STI testing by offering STI testing services closer to the population.

Figure 1

Degree of urbanization (A), ethnic diversity (B), SHC utilization per 1000 residents (C), and SHC utilization by distance to SHC (D). ^a Degree of urbanization of each postal code presented in five categories: very low (<500 addresses/km²), low (500–1000 addresses/km²), moderate (1000–1500 addresses/km²), high (1500–2500 addresses/km²), very high (≥2500 addresses/km²). ^b Level of postal area ethnic diversity ranging from 0 to 1, divided in tertiles; a higher index score reflects more ethnic diversity. The index was based on 10 migratory background groups: native Dutch, other Western residents, Dutch Antillean, Surinamese, Turkish, Moroccans, other non-Western residents, Sub-Sahara African (without Cape Verdean), Cape Verdean and Central and Eastern European. ^c For SHC utilization per postal code, we selected only the first record that fulfilled the inclusion criteria (living in the greater Rotterdam area, aged 15–45 years, tested for any STI) for each individual per year (2015–17). ^d Each dot represents a postal code area. The size of the dots indicate uncertainty; the smaller the dot, the more residents in the postal code area. Postal code areas with ≤5 SHC visitors and/or <200 residents are excluded. km, kilometre; SHC, sexual health centre. The data presented in these maps are based on publicly available data from Statistics Netherlands (figure 1A) or data generated in this study (figure 1B–D)