Implementation fidelity of intravenous ferric carboxymaltose administration for iron deficiency anaemia in pregnancy: a mixed-methods study nested in a clinical trial in Nigeria

Background: Iron deficiency anaemia is common among pregnant women in Nigeria. The standard treatment is oral iron therapy, which can be sub-optimal due to side effects. Intravenous ferric carboxymaltose (FCM) is an evidenced-based alternative treatment with a more favourable side effect profile requiring administration according to a standardized protocol. In this study, we assessed the fidelity of administering a single dose of FCM according to protocol and identified factors influencing implementation fidelity. Methods: We used a mixed-method approach with a sequential explanatory design nested in a clinical trial across 11 facilities in Lagos and Kano States, Nigeria. Guided by a conceptual framework of implementation fidelity, we quantitatively assessed adherence to protocol by directly observing every alternate FCM administration, using an intervention procedure checklist, and compared median adherence by facility and state. Qualitative fidelity assessment was conducted via in-depth interviews with 14 skilled health personnel (SHP) from nine purposively selected health facilities, using a semi-structured interview guide. We analyzed quantitative data using descriptive and inferential statistics in Stata and used thematic analysis to analyze the transcribed interviews in NVivo. Results: A total of 254 FCM administrations were observed across the 11 study sites, with the majority in secondary (63%), followed by primary healthcare facilities (PHCs) (30%). Overall, adherence to FCM administration as per protocol was moderate (63%) and varied depending on facility level. The lowest level of adherence was observed in PHCs (36%). Median, adherence level showed significant differences by facility level (p = 0.001) but not by state (p = 0.889). Teamwork and availability of protocols are facilitation strategies that contributed to high fidelity. However, institutional/ logistical barriers are contextual factors that influenced the varied fidelity levels observed in some facilities. Conclusions: Collaborative teams and access to operating protocols resulted in high fidelity in some facilities. However, in some PHCs, fidelity to FCM was low due to contextual factors and intervention complexities, thereby influencing the quality of delivery. In Nigeria, scale-up of FCM will require attention to staff strength, teamwork and availability of administration protocols, in order to optimize its impact on anaemia in pregnancy.