Using geographic information systems to understand health care access.

BACKGROUND: Determining a community's health care access needs and testing interventions to improve access are difficult. This challenge is compounded by the task of translating the relevant data into a format that is clear and persuasive to policymakers and funding agencies. Geographic information systems can analyze and transform complex data from various sources into maps that illustrate problems effortlessly for experts and nonexperts. OBJECTIVE: To combine the patient data of a community health center (CHC) with health care survey data to display the CHC service area, the community's health care access needs, and relationships among access, poverty, and political boundaries. DESIGN: Georeferencing, analyzing, and mapping information from 2 databases. SETTING: Boone County, Missouri. PARTICIPANTS: Community health center patients and survey respondents. MAIN OUTCOME MEASURES: Maps that define the CHC service area and patient demographics and show poor health care access in relation to the CHC service area, CHC utilization in relation to poverty, and rates of health care access by geopolitical region. RESULTS: The CHC serves a distinctly different area than originally targeted. Subpopulations with unmet health care access needs and poverty were identified by census tract. These underserved populations fell within geopolitical boundaries that were easily linked to their elected officials. CONCLUSIONS: Geographic information systems are powerful tools for combining disparate data in a visual format to illustrate complex relationships that affect health care access. These systems can help evaluate interventions, inform health services research, and guide health care policy. Arch Fam Med. 2000;9:971-978

Evaluating health service equity at a primary care clinic in Chilimarca, Bolivia.

Policy makers and health planners generally support the concept of equitable health care. A focus on who can use a health service, or its potential access, will not necessarily lead to equitable care if people are not willing to avail themselves of the health services offered. Because equity is difficult to operationalize, outcome-based indicators such as the actual utilization of services are advocated as a means to measure equal access. This paper evaluates the utility of linking the concept of equity with a temporal and spatial analysis of clinic users at a micro scale, supplemented by a community survey. Various spatial scales were employed in the analysis. Utilization of the primary care clinic in Chilimarca, Bolivia varied considerably during the first 25 months of operation. Spatially, utilization shifted away from the targeted service area. Within the targeted service area, usage was concentrated in a few blocks of the community and generally diminished with increasing distance from the clinic. The survey further revealed place of origin, length of residence, and language spoken at home as variables differentiating users from non-users. Failure to include the spatial dimension of utilization would lead to different conclusions if only aggregate data were employed. Spatial analysis of output measures is imperfect and does not necessarily deal with all of the access issues related to acceptability. They do, however, begin to isolate areas of a defined geographic area where further investigation would assist in ascertaining, and subsequently addressing, potential problems related to equal access.

Sprouting of A-fibre primary afferents into lamina II in two rat models of neuropathic pain.

Following peripheral nerve section, injured sensory A-fibres into lamina II of the dorsal horn and form aberrant functional synapses. Such structural changes may underlie some of the sensory abnormalities observed in nerve-injured patients, including neuropathic pain. This study compared the ability of intact and injured A-fibres to sprout in two experimental models of neuropathic pain, where the onset and presence of abnormal behaviours indicative of neuropathic pain have been well described. Rats received either a unilateral chronic constriction injury of the sciatic nerve (CCI) or lesion of the L5 spinal nerve (SNL). The central distribution of the injured and uninjured afferents labelled with choleragenoid conjugated to horseradish peroxidase (B-HRP) was examined at different postoperative survival times. In both models, the contralateral uninjured side, used for control nerve or ganglion injections, showed labelling of the L3-6 spinal segments in laminae I, III-V, leaving lamina II unlabelled. In CCI rats, injured sciatic afferents sprouted in lamina II of the L4-5 dorsal horn by 10 days postinjury. In SNL rats, injured L5 afferents sprouted into lamina II of the L4-5 dorsal horn by 24 h postinjury and were robust from 3 to 10 days. In both models, the labelling in lamina II was absent by 4 months. Labelling of the adjacent uninjured saphenous or intact L4 spinal nerve afferents did not reveal A-fibre sprouting. As the time-course of sprouting of injured A-fibres parallels the previously described behaviour interpreted as neuropathic pain in these models, this may be a phenomenon that contributes to sensory abnormalities such as ongoing pain and mechanical hypersensitivity.