Impact of co-packaging oral rehydration salts and zinc on diarrhoea treatment dispensing behaviour in selected rural health facilities in Zambia.

Co-packaged oral rehydration salts (ORS) and zinc for the treatment of childhood diarrhoea was added to the World Health Organization's Essential Medicines List in 2019, to help address the persistently high mortality and morbidity associated with diarrhoea in children under 5 years of age and the low uptake of the recommended co-therapy. However, little empirical evidence exists on how co-packaging impacts dispensing practices in low-resource settings. Here, we present findings from a study conducted in Mongu District, Zambia, aimed at evaluating the effect of introducing a co-pack containing ORS and zinc on dispensing behaviour at rural health facilities. Data from dispensing records were collected before and after the introduction of the co-pack, in 2016 and 2017, respectively, from seven government health facilities. We used multilevel logistic regression to account for the fact that the data is clustered by health facility and to address potential intraclass correlations in dispensing practices within the same facility. The results indicate an overall odds ratio of 8.42 (95% CI: 5.47-12.9) for the dispensing of both ORS and zinc together, for 2017 versus 2016, along with a significant reduction in the variability of dispensing practices between facilities (once the co-pack factor was included). Additionally, the data suggest that less well-resourced facilities experienced the greatest benefit from the introduction of the co-pack. These findings provide valuable insights into the potential of co-packaging to foster appropriate diarrhoea-treatment dispensing practices in resource-limited settings. As such, they provide a foundation for further research to validate them on geographical scales beyond the district level.