Assessment of Implementation Outcome Measures for Positive Deviance Approach as a New Strategy to Promote Exclusive Breastfeeding: A Psychometric Follow-Up Study.

Background: Implementation outcomes are the effects of deliberate actions while implementing new interventions which explain the process and are preconditions to achieve the desired outcomes. Positive Deviance Approach (PDA) was implemented as a new strategy to mitigate the gaps of exclusive breastfeeding (EBF) practice in Jimma, Ethiopia. However, there was no evidence to what extent intervention participants' perceive/rate these outcomes. In addition, psychometric outcome measures lack conceptual clarity, have unknown reliability and validity to the context. Therefore, we aimed to assess implementation outcomes, determine valid and reliable scales and analyze their correlation and variation explained. Methods: A post-implementation follow-up study was conducted between August 28, 2020 and September 30, 2020 among the intervention participants of an earlier trial. A sample of 384 participants was invited to respond to an interviewer (or self)-administered structured questionnaire. The developed tool was refined through experts' comment, pre-test, and using Exploratory Factor Analysis (EFA) to determine the measurement scales, and Total Variability Explained (TVE). The reliability test was done. The mean scores were determined which indicates the extent of each scale's rate. Pearson's correlation, independent sample Results: This study identified nine implementation outcomes of PDA as a new strategy to promote EBF with a TVE 72.1%. 52 valid and reliable items were developed to measure these outcomes. The maximum mean score was for "appropriateness scale" - 27.81 (6.5SD), while the minimum was for "implementation cost scale" - 11.37 (5.2SD). The overall mean score was 164.18 (26.8SD). The emerged scales explained 72.1% of the total variability in implementation outcomes. Majority (6) of outcomes of PDA were highly rated. Implementation fidelity, penetration, organizational readiness, and sustainability scores were positively and significantly correlated with acceptability of the approach. Conclusion: This study identified nine valid, reliable, well explained and correlated implementation outcomes which help to understand the success of PDA as a new strategy to promote EBF. Majority of outcome measures were highly rated by intervention participants, which suggests it is a promising approach in promoting EBF in urban community by PDs.