Evaluating implementation of "management of Possible Serious Bacterial Infection (PSBI) when referral is not feasible" in primary health care facilities in Sindh province, Pakistan.

Health system support was adequate but clinical management and counselling by HCPs was sub-optimal particularly with CSI cases who are at higher risk of adverse outcomes. Scaling up PSBI management is potentially feasible in PHC facilities in Pakistan, provided that HCPs are trained well and mentored, receive refresher training to appropriately manage sick young infants, and have adequate supplies and counselling skills.