Background: Lack of knowledge about family planning is one of the primary hindrance in appropriate decision making about optimum birth spacing and use of contraception for ideal family size. Still, no local tool is available for assessing knowledge about birth spacing among females.

Objective: To develop and validate questionnaire of knowledge about family planning among Pakistani females

Materials and Methods: After the tool was developed using literature search, through expert opinion and personal observation, there were 7 items in the finalized tool. The questionnaire was subjected to Exploratory Factor Analysis (EFA) by collecting data from 35 participants. Face and content validity was ensured and data was analyzed using SPSS version 23 and AMOS version 24. Sphericity, adequacy, Principal Component Analysis with Varimax rotation method was used for EFA. PLS software was used for Confirmatory Factor Analysis (CFA) conducted on 70 participants. Pathway analysis along with Comparative Fit Index (CFI), Root Mean Square Error of Approximation (RMSEA) and other indices using PLS software. P-value<0.05 was considered significant.

Results: The Kaiser-Meyer-Olkin Measure was adequate (0.599; p-value<0.001), the eigenvalue of the significant factor was 3.196 with Cumulative Variance as 85.753. Whilst, Chronbach’s alpha was 0.797. In CFA, the path diagram shows that the standardized regression weights were all > 0.5 and less than 1. (CMIN/ D.F) was 1.309 , and insignificant p-value i.e. > 0.212 (>0.05), the standardized Root Mean Square Residual (SRMR) was 0.0484, the root mean square error of approximation (RMSEA) was 0.067, the comparative fix index (CFI) was 0.983, the goodness-of-fit index (GFI) was 0.947 and the Tucker-Lewis index was 0.967. The values of Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC) were 48.397 and 86.62. Hence, all the indicators were considered good as CMIN/DF between < 3, RMSEA < 0.08, CFI > 0.90, GFI > 0.85, TLI > 0.90

Conclusion: This study developed a validated and reliable questionnaire to assess the knowledge about family planning among females.