Household sampling through geocoded points and satellite view: A step-by-step approach to implement a spatial sampling method for demographic and health surveys in areas without population sampling frame and with limited resource settings

INTRODUCTION

Spatial sampling is increasingly used in health surveys as it provides a simple way to randomly select target populations on sites where reliable and complete data on the general population are not available. However, the previously implemented protocols have been poorly detailed, making replication difficult or even impossible. To our knowledge, ours is the first document describing step-by-step an efficient spatial sampling method for health surveys. Our objective is to facilitate the rapid acquisition of the technical skills and know-how necessary for its deployment.

METHODS

The spatial sampling design is based on the random generation of geocoded points in the study area. Afterwards, these points were projected on the satellite view of Google Earth Pro™ software and the identified buildings were selected for field visits. A detailed formula of the number of points required, considering non-responses, is proposed. Density of buildings was determined by drawing circles around points and by using a replacement strategy when interviewing was unachievable. The method was implemented for a cross-sectional study during the April-May 2016 period in Cotonou (Bénin). The accuracy of the collected data was assessed by comparing them to those of the Cotonou national census.

RESULT

This approach does not require prior displacement in the study area and only 1% of identified buildings with Google Earth Pro™ were no longer extant. Most of the measurements resulting from the general census were within the confidence intervals of those calculated with the sample data. Furthermore, the range of measurements resulting from the general census was similar to those calculated with the sample data. These include, for example, the proportion of the foreign population (unweighted 8.9%/weighted 9% versus 8.5% in census data), the proportion of adults over 17 years of age (56.7% versus 57% in census data), the proportion of households whose head is not educated (unweighted 21.9%/weighted 22.8% versus 21.1% in census data).

CONCLUSION

This article illustrates how an epidemiological field survey based on spatial sampling can be successfully implemented at low cost, quickly and with little technical and theoretical knowledge. While statistically similar to simple random sampling, this survey method greatly simplifies its implementation.

Low use of artemisinin-based combination therapy for febrile children under five and barriers to correct fever management in Benin: a decade after WHO recommendation

Background

Artemisinin-based combination therapy (ACT), used to treat uncomplicated malaria cases, is one of the main strategies of malaria control and elimination. One of the main objectives of the Benin National Malaria Control Program’s (NMCP) strategic plan is to ensure that at least 80% of uncomplicated malaria is treated with ACT within 24 h. Therefore, it was of great interest to measure whether the country case management of fever amongst children under five, adhered to the NMCP’s strategic plan and look into the barriers to the use of ACT.

Methods

A cross-sectional survey based on a cluster and multi-stage sampling was conducted in two rural health districts in Benin. We recruited 768 and 594 children under five years were included in the northern and in the southern respectively. Data was collected on the general use of ACT and on the correct use of ACT that adheres to the NMCP’s strategy, as well as the barriers that prevent the proper management of fever amongst children. To assess the certain predictors of ACT usage, logistic regression was used, while taking into account the cluster random effect.

Results

Among febrile children aged 6 to 59 months, 20.7% in the south and 33.9% in north received ACT. The correct use of ACT, was very low, 5.8% and in southern and 8.6% northern areas. Caregivers who received information on ACT were 3.13 time more likely in the south and 2.98 time more likely in the north to give ACT to their feverish child, PPR = 3.13[1.72–4.15] and PPR = 2.98 [2.72–3.11] respectively. Chloroquine and quinine, other malaria treatments not recommended by NMCP, were still being used in both areas: 12.3 and 3.3% in the south and 11.4 and 3.0% in the north.

Conclusion

In Benin, the use and the correct use of ACT for febrile children remains low. The study also showed that having received information about the use of ACT is positively associated with the use of ACT. This point highlights the fact that efforts may not have been sufficiently integrated with social communication, which should be based on the behavioural determinants of populations.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5077-6) contains supplementary material, which is available to authorized users.

Effets de l’amélioration de l’offre de soins sur l’activité d’un poste de santé en zone rurale au Sénégal

BACKGROUND

This study aimed at analyzing the short-term effects of an improvement in care offer on dispensary activity in a rural area of Senegal.

METHODS

The Niakhar health center, situated 150 km east of Dakar, underwent significant changes during the years 1998 and 1999: a hospital unit was built, the maternity ward was extended and the patient reception facilities were refurbished and reorganized. We examined dispensary registers before (1997) and after (2000) this period of time. We focused on data reporting activity and utilization of the health center. We also studied the users'perception of these improvements. Interviews were conducted with 39 families to measure the consequences of this change on their attitudes towards treatment.

RESULTS

The number of consultants increased by 49.8% from 1997 to 2000. Activity peaked during the rainy season, during which consultations were twice as numerous in 2000 as in 1997. However a similar increase was noticed in another health center close to Niakhar and could be attributed to the high precipitation rate observed in this area in the year 2000. For children, there was no difference in center utilization between the two study years as each child went to the dispensary 1.18 and 1.21 times a year in 1997 and 2000 respectively. The maternity activity exhibited a 68% increase in deliveries. Families interviewed said the dispensary was significantly improved, but they were not able to change their practice, due to lack of financial resources and poor drug supply.

CONCLUSION

The changes in care offer did not seem to have yielded the expected effect on care activity. The appointment of a midwife as well as improvements in both technical facilities and awareness contributed to the increase in maternity use.