The present study was conducted with an analytical cross-sectional design. In this research, sampling is done in a convenient and Continuous method. Sampling was done from 16 October to 9 February 2021 in 3 urban health centers of Shiraz. To determine the required sample size at a confidence interval of 99% (
= 2.58) with an acceptable error (\(d\)) of 1.45 (2.5% Mean: 58.11) and a standard deviation (\(\sigma )\) of 7.90 for postpartum quality of life in Iran (30), 198 people were estimated by quantifying in the following formula (31). The researchers included 240 women in the study because of the sample size was suitable for performing structural equation modeling (SEM) (32).
Women are selected who; 1) no mental retardation, 2) no physical disability, 3) literacy for reading and writing, 4) had a live birth at least 1 month and up to 18 months ago. After stating the objectives of the study for women, obtaining a written informed consent form from women, and explaining how to complete the questionnaires, asked them to complete the questionnaires within 30 minutes.
Data collection tools included two questionnaires: The Persian version of the postpartum quality of life questionnaire (PQOL) (30), and the family social support questionnaire (FSSQ) (33). The Persian version of PQOL has validity of 0.88 through Cronbach's alpha calculation and validity of 0.77 through KMO and Bartlett's test at the level of p < 0.001(30). This questionnaire has 4 dimensions and 40 questions, the dimensions of which are: 1- Child care dimension with 8 questions, 2- Physical function dimension with 12 questions, 3- Psychological function dimension has 8 questions, 4- Social support dimension has 12 questions. The answering to the questions of the questionnaire was on the 5-point Likert scale in the form of intensity ([1] not at all, [2] slightly, [3] moderately, [4] very, [5] extremely); frequency ([1] never, [2] rarely, [3] sometimes, [4] often, [5] always); and evaluation ([1] very dissatisfied, [2] dissatisfied, [3] neither satisfied nor dissatisfied, [4] satisfied, [5] very satisfied) which were scored by the method of the original version between 0-100 that lowest score indicates the unfavorable situation and the highest score indicates the favorable situation. First, the score of each item was transformed from 0 to 100 (0–100 scale) by using the formula of transformed scale = \(\frac{\text{a}\text{c}\text{t}\text{u}\text{a}\text{l} \text{r}\text{a}\text{w} \text{s}\text{c}\text{o}\text{r}\text{e}-\text{l}\text{o}\text{w}\text{e}\text{r} \text{p}\text{o}\text{s}\text{s}\text{i}\text{b}\text{l}\text{e} \text{s}\text{c}\text{o}\text{r}\text{e}}{\text{p}\text{o}\text{s}\text{s}\text{i}\text{b}\text{l}\text{e} \text{r}\text{a}\text{w} \text{s}\text{c}\text{o}\text{r}\text{e} \text{r}\text{a}\text{n}\text{g}\text{e}} \times\)100, then the score of each domain and the total score of the questionnaire was obtained from the mean scores of the items and domains respectively (15).
The social support questionnaire with a validity of 97. 0 through Cronbach's alpha calculation and validity of 0.921 through KMO and Bartlett's test at the level of p < 0.0001 (33). This is a researcher-made questionnaire retrieved from SSQ, BSSS, and PFUK questionnaire called "Family Social Support Questionnaire" (FSSQ) with 79 questions in 4 dimensions, which are: 1- Emotional support, including 25 questions about perceived, received and needed support, 2- Instrumental support, including 9 questions about including needed support, 3- Informational support, including 16 questions about perceived and received support. 4- Family support seeking including 29 questions about emotional, instrumental and informational support. The questions are answered in the form of Likert scores and four grades. The four degrees of the "strongly disagree" [1], "disagree" [2], "agree" [3], "strongly agree" [4] were included, which in the present study for better analysis and understanding transformed to the score of 0 to 100 (15).
Answering all the questions of the questionnaires is self-reporting. After extracting the data, descriptive statistics such as frequency, mean, median, and standard deviation were used for demographic data. Analytical statistical tests including the Pearson correlation and multivariate regression were used to determine the relationship between variables. The SEM was used to path mapping and measurement accuracy of impact of FSS on PQOL as latent variables. All calculations were performed with SPSS software version 25 and Amos software version 24 (34,35).