Objective
This study aimed to translate and assess the psychometric properties of the Women’s Satisfaction with Childbirth Education Classes questionnaire.
Study participants
The participants included all primiparous or multiparous pregnant women with the gestational age of 35-37 weeks participating in childbirth preparation classes.
Sample Size
A total number of 5 samples per item were selected as the participants (125 samples for the 25-item questionnaire); however, considering the design effect of the cluster sampling method and a 10% loss to follow-up rate, 205 individuals were selected as the sample.
Instrument
Women’s satisfaction with the childbirth education class questionnaire was utilized to collect data on mothers’ satisfaction with childbirth classes. In this 25-item instrument, all items are scored on a five-point Likert scale ranging from “not at all satisfied” (score 1) to “very satisfied” (score 5). The thematic domains of the questionnaire include the class structure (questions 1-5), the class process (questions 6-21), and the class outcome (questions 22-25).
Translation process
The original version of the instrument was first translated from English into Persian by a native English translator, who also masters Persian. Then, the researchers reviewed this version of the questionnaire. In the next phase, the Persian version was translated into English by two professional translators mastering both languages who had not participated in the previous stage. The final questionnaire was prepared after two individuals who were familiar with specialized medical terms and mastered both languages reviewed the final English version.
Data Collection
The research protocol of this study was published in 2019 [14]. The participants were selected in 2019- 2020 through the cluster sampling method. First, 7 (out of 20) health complexes of Tabriz were selected through simple random sampling. The participants were then selected from all pregnant women admitted to the health centers affiliated with the selected complexes (Each health complex consisted of 4-5 health centers. Samples were selected from 29 centers). The eligible women with gestational age of 35-37 weeks were selected from each center through proportional allocation. After the eligible women were enrolled, they were informed about the research objectives and method, and the informed consent forms were signed by those who were willing to participate in the study. The socio-demographic and satisfaction with childbirth preparation classes questionnaires were completed after the participants were interviewed. The socio-demographic questionnaire included items about a mother’s age, her educational degree, and her job, her spouse’s educational qualifications and job, her household income status, and the type of pregnancy (i.e. wanted or unwanted pregnancy). The validity of this questionnaire was confirmed through the measurement of its content validity.
Face and content validity
To assess the face validity of the questionnaire, 20 randomly selected pregnant women were asked to rate the difficulty, relevance, and ambiguity of all questions. The responses were scored on a four-point Likert scale ranging from 1 (completely difficult/irrelevant/ambiguous) to 4 (completely simple/relevant/unambiguous). The respective impact score for each item was then calculated through this formula: importance (mean score of each item) * frequency (number of responses 4). An impact score of > 1.5 for an item was considered acceptable.
Content validity was assessed through qualitative and quantitative methods. In the qualitative phase, 10 midwifery and reproductive health specialists were asked to review the translated questionnaire and provide corrective feedback on the use of correct grammar, vocabulary, and phrases in each sentence. CVR and CVI were used in the quantitative phase. CVI values were calculated through determining the relevance, unambiguity, and simplicity of the items and scoring them on a four-point Likert scale. A CVI value higher than 0.79 was considered acceptable. To determine CVR scores, the experts were asked to comment on the necessity of each item by using a four-point scale. Based on the Lawshe Table, the minimum acceptable CVR value was determined as 0.62.
Construct validity
A scale-based EFA and a CFA were performed to assess the construct validity of the questionnaire. Factor analyses were also performed for the items at the subscale level as well as the whole questionnaire.
EFA was performed through the Kaiser-Meyer-Olkin (KMO) test and Bartlett’s test of sphericity. Values above 0.7 confirm the adequacy of the data for conducting EFA [15]. In addition, eigenvalues and scree plot were utilized to determine the number of factors. An eigenvalue is a measure that determines the amount of variance in a dataset explained by a factor; therefore, factors with higher eigenvalues explain more variance [16].
Factor analysis assesses inner-variable relations and is used to extract a group of items that are most closely related to each other. In this analysis, items with factor loadings of < 0.3 were omitted, and the research team decided whether to accept or omit those with factor loadings between 0.3 and 0.5 [16].
Confirmatory factor analysis
To assess the structure of factors obtained from the exploratory factor analysis, the model was fitted using the confirmatory factor analysis. This factor analysis investigates the confirmation of the exploratory model theoretically and the relationship between factors. The fitness of indices was used to evaluate the model fitness. To confirm the model by these indices, Root Mean Square Error of Approximation (RMSEA) was considered lower than 0.08, Standardized Root Mean Square Error of Approximation (SRMSEA) < 0.08, Comparative Fit Index (CFI) ≥ 0.90, Tucker- Lewis Index (TLI) ≥ 0.95, Normed Chi-square (x2/ df) < 5.0.
Reliability
Internal consistency and test-retest reliability were measured to determine the overall reliability of the questionnaire. Internal consistency was assessed by calculating Cronbach’s alpha in a sample of 20 mothers. The test-retest reliability was also assessed by calculating ICC for the same participants who completed the questionnaire twice at a two-week interval.
Ethical consideration
This study was taken from a PhD thesis in midwifery approved by the Ethics Committee of Tabriz University of Medical Sciences (Ethics code: IR.TBZMED.REC.1398.066). Informed written consents were obtained from all the participants.