Psychometric properties of women’s satisfaction with the childbirth education class questionnaire for Iranian population

Background: Childbirth preparation classes can reduce pregnant women’s anxiety and fear levels by providing them with training supports. The importance of mothers’ participation in these classes, evaluation of their satisfaction with these classes, and lack of a standard instrument in Iran led to the necessity of conducting this study for the translation and psychometric analysis of the women’s satisfaction with the childbirth education class questionnaire for the population of Iranian women. Methods: The questionnaire was translated from English into Persian through the forward-backward translation method. The cluster sampling method was employed to select 205 pregnant women with gestational age of 35-37 weeks from all health complexes of Tabriz, Iran. The face, content, and construct validity of the research instrument were assessed through exploratory and confirmatory factor analyses. Internal consistency and test-retest reliability were measured to evaluate the overall reliability of the questionnaire. Results: The impact scores of all items were above 1.5. The content validity index (CVI) and content validity ratio (CVR) of the questionnaire were 0.88 and 0.94, respectively. The convergent construct validity of the whole questionnaire and those of its three subscales were confirmed through the exploratory factor analysis (EFA). The factor loadings of no items were below 0.3, and the X2⁄df ratio was smaller than 5. In addition, the RMSEA was smaller than 0.08; therefore, the overall model validity was confirmed. Cronbach’s alpha and intra-class correlation coefficient (ICC) were 0.93 and 0.96, respectively, indicating the acceptable reliability of the questionnaire. Conclusion: The Persian version of this questionnaire, entitled "Women’s Satisfaction with Childbirth Education Class" is a valid and reliable instrument for measuring Iranian women’s satisfaction with childbirth education classes.

emphasizes natural childbirth without unnecessary interventions and supports prenatal maternal education and active participation of mothers in the childbirth process [5]. In some studies, women who participated in childbirth preparation classes managed to adapt better to labor pain, used fewer labor medicines, and had fewer instrumental deliveries [6][7][8]. Today, women tend to manage their own labor, control their delivery, use non-pharmacological pain management techniques, and experience a good delivery by sharing this special experience with their family [9]. Lee and Holroyd's findings showed that pregnant women attending childbirth preparation classes could better manage their pregnancy, childbirth, and postpartum period than those who merely received routine care [10].
In the past, prenatal care services provided in Iran were limited to regular examinations, routine tests, and sonography. However, these services were inadequate, and lack of awareness and fear of unknowns of pregnancy and delivery led to maternal anxiety and various complications and increased medical interventions [11].
In this respect, the Iranian Ministry of Health and Medical Education has been conducting physiological delivery preparation classes in different cities since 2008. The classes are held in eight sessions from week 20 to week 37 of pregnancy. At the beginning of each session, mothers are provided with various pieces of information (based on their gestational age) such as the anatomy of their reproductive system, physiological adaptations during pregnancy, fetal development, prenatal care and nutrition, physical and mental health, pregnancy risk factors, benefits of natural childbirth, pain relief techniques, postpartum examinations and risk factors, and infant care. In the second part, a counseling question-and-answer session is held. In the third part, mothers learn various skills such as stretching exercises, posture correction exercises, relaxation methods, massages, and breathing techniques [12]. These classes have been held in many countries for years; however, few studies have evaluated mothers' satisfaction with these classes. Although mothers' satisfaction is an important indicator of prenatal activities [13], no Iranian studies were found on this topic.
In a mixed-method study in China, Lee et al. used an instrument to evaluate mothers' satisfaction with prenatal education classes. In the quantitative phase, they reviewed the research literature and developed a self-report questionnaire to assess women's satisfaction with those classes. This 25-item 4 questionnaire consisted of three subscales of structure, process, and outcome and focuses on mothers' satisfaction with childbirth preparation classes. The items were scored on a five-point Likert scale ranging from "not at all satisfied" (score 1) to "very satisfied" (score 5) [10].
Given the importance of prenatal educations, mothers' satisfaction with childbirth preparation classes, and lack of a standard instrument for measuring satisfaction levels of Iranian women, this study translated the questionnaire entitled Women's Satisfaction with Childbirth Education Class and assessed its psychometric properties.

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.

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 fourpoint 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, 6 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

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

Results
A total number of 205 mothers were enrolled from May 2019 to December 2020. The mean (SD) age of the participants was 27 (5.2) years, and most of the participants (80.5%) were housewives. Table 1 presents the other pieces of information.

Face and content validity
In Iran, birth preparation classes are taught by trained midwives; hence, the researchers decided to replace "physiotherapist performance" and "anesthesiologist performance" with "midwife performance" in training massage and pain reduction techniques in Items 7 and 8 with. All items were described as relevant, unambiguous, and simple, and their impact scores were all above 1.5; therefore, the face validity of the instrument was confirmed. The resultant CVI and CVR values of all items were acceptable. In addition, the CVR and CVI values for the whole questionnaire were 0.94 and 0.88, respectively (Table 2).

Reliability
Cronbach's alpha coefficients of the assessed constructs were between 0.83 (the class structure) and 0.92 (the class outcome), and a coefficient of 0.93 was obtained for the whole questionnaire.

Exploratory factor analysis
EFA was performed in two steps. The first step was carried out for each subscale, separately. KMO values for the subscales of the class structure, the class process, and the class outcome were 0.818, 0.921, and 0.794, respectively. Bartlett's test P-value was smaller than 0.001. These results confirm the data adequacy for performing a scale-based EFA. Based on scree plot, items of each subscale load only on one factor; thus, the convergent construct validity was confirmed for all subscales. The total variance explained values for the three subscales were 71.74, 60.774 and 67.967, respectively. The second step of EFA was performed for all subscales at the questionnaire level, at which KMO value was 0.647, and Bartlett's p-value was smaller than 0.001. Based on the results, the assessed questionnaire can be predicted by three factors by considering a maximum total variance of 80.83 ( Figure 1). In addition, since each subscale loads only on one factor (based on scree plot), the convergent construct validity was confirmed for the whole questionnaire. Factor loadings obtained for all items were larger than 0.3; therefore, none of the items were omitted (Table 3). Factor loadings for all the subscales were also above 0.3 (Table 4).
Regarding the CFA results, Table 5 shows goodness-of-fit indices. The X 2 ⁄df ratio was above 5, and RMSEA was below 0.08; therefore, the overall validity of the model was confirmed. Moreover, all goodness-of-fit indices (including GFI, AGFI, NFI, NNFI, RFI, IFI, and CFI) were greater than 0.9, indicating that the research model fits the data well. The correlations between all factors were significant (P<0.05) ( Table 6). Figure 2 depicts a path diagram with standardized coefficients representing the conceptual research model.

Discussion
This study assessed the psychometric properties of women's satisfaction with the childbirth education class questionnaire for Iranian pregnant women. According to the results, the Persian version of this questionnaire is a reliable and valid instrument for assessing Iranian pregnant women's satisfaction with childbirth education classes. To assess the psychometric properties of this instrument, its validity was confirmed through quantitative and qualitative face and content validity as well as the construct 9 validity (EFA). The reliability of the questionnaire was also assessed through internal consistency (Cronbach's alpha) and test-retest reliability.
Based on the EFA results, none of the items were omitted because factor loadings for all items were acceptable. In the psychometric assessment of the Persian version of the questionnaire, three factors of the original questionnaire were confirmed. Construct validity refers to an instrument's ability to measure the target concept and/or conceptual structure. Factor analysis is a commonly used technique for assessing construct validity [17].
KMO was used as a measure of data adequacy for EFA. KMO values for the subscales of class structure, class process, and class outcome were 0.818, 0.921, and 0.794, respectively, and KMO value for the whole questionnaire was 0.647. KMO values from 0.9 to 0.1, 0.8 to 0.89, 0.7 to 0.79, 0.6 to 0.69, and 0.5 to 0 are considered very suitable, suitable, acceptable, mediocre, and poor, respectively [18].
The minimum factor loading required to accept an item in a subscale depends on the number of items, scales, and eigenvalues. Factor loadings between 0.3 and 0.4 were considered acceptable [19], and those ≥ 0.6 were considered very high [20]. In this study, the calculated factor loadings ranged from 0.42 to 0.89, an interval indicating high validity of the items.
CFA was performed to assess the construct validity of the instrument. In this respect, it is necessary to have a good understanding of appropriate events, which are independent assessment indices [21].
The chi-square (X 2) test results indicate whether there is a significant difference between the implied and the observed covariance matrices [22]. In this study, the observed matrix was compatible (P < 0.05). X 2 ⁄df ratios lower than 3 indicate good compatibility, and those lower than 5 indicate moderate compatibility. A ratio of 3.69 was obtained in this study, a finding which indicates moderate compatibility. The obtained goodness-of-fit indices including GFI, AGFI, NFI, NNFI, RFI, IFI, and CFI were > 0.9, a finding which indicates that the research model fits the data well [23].
The resultant Cronbach's alpha coefficients for the constructs of class structure (0.83), class process Measuring satisfaction levels is a very common step in many assessments [24]. Services that provide lower levels of satisfaction are less effective because dissatisfaction is accompanied with incompatibility with medical guidelines, delayed search attempts for medical care, and poor understanding of medical information [25], whereas satisfied individuals continuously seek to receive satisfactory care [26]. The results of this study can help authorities and planners develop better plans and conduct childbirth preparation classes.

Strengths And Weaknesses
This was the first study conducted in Iran to assess the psychometric properties of women's satisfaction with the childbirth education class questionnaire. Analyzing primiparous and multiparous women was among other strengths of this study, which was carried out in Tabriz, Iran. Therefore, researchers are recommended to conduct similar studies in other areas with different cultures as well as the rural areas of Iran. Regarding research weaknesses, the same data were used for performing EFA and CFA. Finally, to enhance the external validity of the study, researchers can carry out analyses on other datasets; however, a large sample must be selected and divided into two sub-samples to estimate stable parameters [27].

Conclusion
The results showed that the Persian version of women's satisfaction with the childbirth education class questionnaire was a valid and reliable instrument for measuring pregnant women's satisfaction with childbirth education classes. This instrument can help health authorities and caregivers measure pregnant women's satisfaction with these classes and make necessary interventions to provide further support for pregnant women in such classes.

Consent for publication
Not applicable.

Availability of data and materials
The datasets used and analysed during the current study are available from the corresponding author on reasonable request.    Figure 1 Scree Plot for subscales 19 Figure 2 CFA factor loading