Data
Service Provision Assessment (SPA)
This analysis used data from the SPA to generate nationally representative data on health service delivery [12, 19]. The SPA includes a standard set of survey instruments: a facility inventory questionnaire, health worker interviews, observation of ANC consultations, and exit interviews with ANC clients.
We examined all SPA surveys for inclusion in the analysis (total of 31). We included all SPA surveys that were available for public use as of early 2018 which used the Demographic and Health Surveys (DHS)-VI or DHS-VII questionnaire (14 surveys excluded), that included observations of ANC consultations (six surveys excluded), were conducted in the last 10 years (between 2012 and 2022; two surveys excluded), and were the most recent survey for the country meeting inclusion criteria (1 survey excluded). The included surveys are from Haiti (2013), Malawi (2013/2014), Nepal (2015), Senegal (2016), and Tanzania (2014/2015). Comprehensive information on the survey methodology and questionnaires is detailed in the SPA final country reports [20-24]. In Nepal, Senegal, and Tanzania, the survey was a nationally representative sample of health facilities selected using stratified systematic probability sampling with stratification by administrative area (geo-ecological region and development-ecological zone in Nepal, and region in Tanzania) and facility type (with oversampling of some facility types such as hospitals). In Haiti and Malawi, the survey was comprised of a national census of all health facilities. The facility inventory module was completed by all surveyed facilities in the five countries. Additionally, up to eight health workers were interviewed within each facility. Selected health workers include those whose consultations were observed and those who provided information for any section of the inventory questionnaire. Sampling of clients for observation was done using systematic sampling and was dependent on the number of clients present at each service site on the day of the visit. For facilities where the number of ANC clients could not be anticipated, opportunistic sampling was used when clients arrived. At a minimum, five client observations were completed per service provider, with a maximum of 15 observations in any given facility for each service. Client exit interviews were conducted following each client-provider observation.
Analysis
In order to standardize expected clinical actions, we limited this analysis to facilities offering ANC services with at least one first ANC client observation, and to women attending the health facility for a first ANC visit. We did not include observations containing incomplete data. Supplementary Table 1, Additional File 1 provides information on the full sample size and analytical sample size for each country.
To assess the effect of excluding incomplete cases, we compared facilities, health workers, and ANC clients with and without complete data across background characteristics. For continuous variables, we calculated means and used t-tests to assess differences between groups. For categorical variables, we calculated proportions and used chi-square tests to assess differences between groups. There were no statistically significant differences between the groups. Supplementary Table 2, Additional File 1 provides the details of the all cases versus complete cases analysis.
Facility readiness and provision of care indices
As described previously by Sheffel et al, we created nine indices for facility readiness using three methods for selecting items (core set of items, expert survey set of items, and maximum set of items) and three methods for combining items (simple additive, weighted additive, and principal component analysis (PCA)) [25]. In addition, we created a provision of care index using the expert survey set of items for selecting items and a weighted approach to combine items (Figure 1). A detailed description of item selection, item combination, and index creation are described in Sheffel et al [25]. The distribution of readiness scores and provision of care scores for each country are presented in Supplementary Figure 1, Additional File 1 and Supplementary Figure 2, Additional File 1.
Standardization of facility and health worker level variables
Facility-level variables such as facility type and managing authority were standardized across the five surveys. For facility type, three categories were constructed — hospital, health center/clinic, and dispensary. Since facility size is often associated with facility type, we conducted descriptive analyses of the number of total staff and the number of inpatient beds per facility type in order to determine which facility types were most similar in size. Supplementary Table 3, Additional File 1 provides details of this analysis. For managing authority, we created three categories — government/public, private (non-faith based), and private faith based. At the health worker level, qualification was standardized across the surveys into three categories — physicians, clinical officers, and nurses/midwives (Supplementary Text, Additional File 1 provides cadre definitions).
Additional covariates
We included facility, health worker, and individual characteristics as covariates in our regression models. Facility-level covariates included facility type, managing authority, urbanicity, and average number of staff. Health worker-level covariates included qualification and gender. Individual-level covariates included the number of weeks pregnant, if the client had a previous pregnancy, age, and the highest level of education attained by the client. For Nepal, the covariate urbanicity was excluded as this data was not collected in the Nepal survey. For Haiti and Senegal, the covariate number of weeks pregnant was excluded because more than 50% of the data was missing for this item.
Regression analysis
To assess the association between provision of care and facility readiness, we first conducted a bivariate regression of provision of care on each facility readiness index described above. This analysis was conducted at the client level using a multilevel linear regression model with random effects for facility and health worker. Next, we used a multilevel, multivariable linear regression model with random effects for facility and health worker, controlling for facility, health worker, and individual characteristics. We ran nine separate models, one for each facility readiness index. The outcome in each case was the same provision of care index. Analyses were conducted separately for each country. Visual examination of the data suggested a possible inflection point around a readiness score of 50 (see Supplementary Figures 3-12, Additional File 1); we tested this by fitting linear spline models with a single knot at 50 for all countries except for Senegal where there were few facilities with readiness scores below 50. For each model, we divided the coefficient for the readiness index by the standard error to obtain a measure of the strength of the association that accounts for both the estimate and the standard error.
To compare the coefficients between models, we used a bootstrapping approach. For each dataset, we generated 500 independent survey samples by resampling facilities with replacement, selecting the same number of facilities as in the original survey. Then, we merged the sampled facilities with client data to get sampled clients for the client-level analysis. For each of the 500 samples, we ran the nine linear models and nine linear spline models. We then calculated the mean difference of the coefficient for facility readiness and the standard deviation of the mean difference for each of the 36 pairwise comparisons. Statistical significance was determined using a Bonferroni adjusted p-value to account for the multiple pairwise comparisons.
Finally, we collapsed the individual-level dataset into a facility-level dataset by taking the mean index score across clients within a facility and conducted a multivariable linear regression adjusting for facility characteristics. We then compared the facility- and individual-level analyses using the same bootstrapping approach.
All statistical analyses were carried out using R version 4.1.3 [26].