Sensitivity of Hospital-Based Surveillance for Severe Disease: A Geographic Information System Analysis of Access to Care in Kilifi District, Kenya/Sensibilite De la Surveillance Hospitaliere Des Maladies Graves: Une Analyse Du Systeme D'information Geographique De L'acces Aux Soins Dans le District Kilifi Au Kenya/Sensibilidad De la Vigilancia Hospitalaria De Enfermedades Graves: Analisis

Introduction In addition to a focus on the Millennium Development Goals--specifically Goal 4, which aims for a two-thirds reduction in under-5 mortality between 1990 and 2015--the child survival agenda in developing countries is increasingly driven by equity considerations. (1,2) Regional and country-level analyses have investigated the socioeconomic and spatial determinants of health inequities and have demonstrated that lower-income and rural populations frequently experience worse child survival rates than their wealthier, more urban counterparts. (3-6) However, limited data are available at the district level to help identify geographic inequities in health outcomes and target the delivery of services to disadvantaged populations. (7,8) In rural settings with a low density of health facilities, physical access to sources of care is a known determinant of health-care utilization, with substantial decreases in rates of clinic attendance observed with increasing from the homestead to the clinic; (9-19) this phenomenon is frequently termed distance decay. However, studies have not directly linked to health facilities to morbidity rates in the community. High utilization rates in areas close to clinics could therefore partially reflect higher rates of disease rather than better access, as would be the case, for example, if deliberately or coincidentally sicker people lived closer to clinics or if clinics were located in areas of higher disease risk. Moreover, decay is generally less marked for hospitals providing inpatient services than for primary care clinics, (11,15,20) suggesting that disease severity may modulate the effect of on care-seeking and ultimately limit its impact on mortality. In Kilifi district, Kenya, we found no effect of to hospitals or vaccine clinics on child mortality, (21) a finding consistent with the results of a study from the Gambia (22) bur not with analyses from rural areas of Burkina Faso, (23) the Democratic Republic of the Congo (24) or the United Republic of Tanzania. (25) Regardless of their impact on mortality, physical and other barriers to healthcare seeking are widely assumed to lead to incomplete disease ascertainment in hospital and to limit the sensitivity of hospital-based surveillance. Disease incidence rates observed in sentinel surveillance systems therefore systematically underestimate the true incidence of disease, and this complicates national and global disease burden estimation. Measuring access to care may enable us to evaluate the sensitivity of surveillance and improve on current estimates of disease burden. In this study we aimed to characterize spatial variations in hospitalization rates in Kilifi district for several diseases, identify areas with low utilization of inpatient services, and link this information to mortality rates to define access to care parameters by health condition and geographic area and estimate the sensitivity of hospital-based surveillance. Methods This analysis relied on data collected routinely by the Epidemiologic and Demographic Surveillance System (Epi-DSS) of the KEMRI-Wellcome Trust Research Programme in Kilifi district, Kenya. The Epi-DSS includes a demographic surveillance system covering an area measuring 900 [km.sup.2] around Kilifi District Hospital (KDH) linked to hospital-based epidemiological surveillance. Study site Kilifi district is a poor, primarily rural district on the Indian Ocean coast of Kenya that enjoys a tropical climate, with two rainy seasons and two dry seasons each year. Mortality in children less than 5 years of age has decreased in recent years but remains high at 65 deaths per 1000 live births. (21) KDH serves as a primary care centre and first-level referral facility for the entire district. Inpatient care is available at three other hospitals in Kilifi district, at Malindi District Hospital in Malindi and at Coast Provincial General Hospital in Mombasa. …