In this study, the entire data gathering designated herein was confirmed by the University of Tarbiat Modares - International Standard Randomized Controlled Trial. Every one of the pregnant women taken written understanding consent former to taking part in this study. We assessed the document for validity and simultaneous test-retest reliability from two independent groups of nulliparous women.
The participants and study
Because of the scale in a broad setting, a cross-sectional study was performed in health centers in Tehran, Iran, between January and March 2019. In this study, the inclusion criteria involved aged between 28 to 35 years, having literacy, have no background of severe complications of the disease, physical inactivity during pregnancy. To collect the data in this study, educated interviewers accomplished face-to-face discussions and interviews. Reference number: Trial ID: ISRCTN13356179/ URL: https://doi.org/10.1186/ISRCTN13356179
Data Collection
The survey applied a sample of 400 pregnant women participating in a study for further validity in a period at the Tarbiat Modares University, Tehran. This group was pregnant women that were in two and three trimesters, and the pastoral age was 20 (M¼20.30, SD¼3.93). The dissemination of racial for pregnant women was 97.2% of Asian and 2.8% minority. The determinants instruments (Perceptions, Nurtures, and Enabling) and the behavior (to be active) measure were managed as a section of the power of questionnaires and surveys with samples of concerning 400 pregnant women. In this survey, the questionnaire's moderator studies all the instructions and items to the center using standardized writing [30]. The writing contained a preface in which exercise was determined as "any kind of moving games, energetic play, sports, or physical activity that gains you acting, rapid breathing, and your heart racing faster." Advertising pictures demonstrating the range of conceivable exercise (e.g., swimming, dancing, running, and acting on the playground, biking, track and field, running, physical activities) companioned this presentation. The questionnaires were managed in the first course of the day whenever the midwives stayed in the health centers. Evaluations were accomplished anonymously, and nulliparous women had the choice to skip any item using the choice “I choose not to answer.” Through each of the pregnant women, average (mean) scores were computed for every changeable presented 80% of the questions were responded on a defined subscale or scale. If a pregnant woman responded less than 80% of the questions, or items on a subscale or scale, afterward, a total score was not computed for that variable. Based on the information provided on these criteria, among 0% and 5% of nulliparous women were missing measure grants for particular variables (the scale of attitude was the most current missing variable findings from the 80% short cut). In this section, after data collection, the test-retest was chosen to develop the questionnaire with a proper subset of the identical sample (n=45). Eventually, the test-retest reliability questionnaires were managed with the identical protocol two weeks separate.
PEN3 Physical Activity Questionnaire
A 24-h summoned questionnaire was developed to assess exercise between nulliparous women in two and trimester registered in the PEN3 Survey. The questionnaire-based on PEN3 physical activity assessed perceptions, nurtures and enabling factors the woman participated in that to tend to lack of physical activity during pregnancy, including knowledge, attitude, social support, and environmental barriers, doctor's advice, wife and family consent, and both inward and out-of-door housekeeper processes which do not allow for physical activity. For example, the query requested: “I believe that with exercise, I can easily deal with problems such as gestational diabetes.” For each activity in these questions, the participant reported the nurtures factors using the accordance options: ‘strongly agree,’ ‘agree, ‘neutral,’ disagree,’ strongly disagree.'
Participants/Setting
All 400 nulliparous pregnant women in five districts of Tehran in Iran (composed of nulliparous pregnant women in 21 categories) were asked to participate. Almost 85% of the people. In other words, 400 pregnant women participated with racial segregation of 89% Iranian-Asian and 9% Afghani-Asian (2% unknown). In this case, Forty-five percent of participants were qualified free or diminished lunch. Finally, an aware satisfaction of pregnant women was received from all of them.
Development of Questionnaire and Testing the Pilot
The PEN-3 cultural model based on Theory provided the theoretical foundations for the instruments developed in this study. First, instruments previously used and tested with adults were identified. The perception scale was taken from the "beliefs about the consequences of participating in" physical activity from the "attitude toward the behavior" component of the PEN-3 cultural model [17]. This component also corresponds to barriers to physical activity in pregnant women. The Social Influences scale included items addressing the nurtures of others from the PEN-3 cultural model [17].
After conducting individual interviews and performing two focus group discussions with 40 pregnant women, the first questionnaire was designed based on the cultural PEN-3 model. Which includes the structures of perceptions, enablers, and nurtures, then primary concepts being measured, and sample items of final instruments are presented in Table 1.
The instruments went through a series of three pilot tests conducted in a health center setting with nulliparous pregnant women demographically similar to the study population. The initial pilot test indicated that pregnant women had difficulty understanding the wording of some items, tiny words for reading, and lengthy questionnaire sentences. Changes made to the primary instruments during the first pilot test included selecting short appropriate words and putting instruments in a visually more appealing format (giant print, more full margins). The subsequent two pilot tests refined and reduced the instruments' size by eliminating items that pregnant women did not understand. The administration time of the final instrument was about 20 min.
Scale development
The initial scale included of 41 items. These aspects included awareness of physical activity, attitude, nurtures, enabling, and barriers factors that effect on inactivity during pregnancy. Item response options in perceptional factors were on the Triploid scale (Yes, No, I do not know) also for nurtures and enabling factors as a 7-point scale from one (strongly disagree) to five (strongly agree) Table 1. Subsequently, a panel of 12 experts in the field of health education and health promotion, gynecologist, and physical activity inquired the original questionnaire. The expert was requested to the explanation on specific questions in connection to the resolution, clarification, and method. The items on the questionnaire were insignificancy modified according to panel reviews. Afterward, a various kind of 20 experts on health education and health promotion was requested that independently to the explanation of the relevance and necessity of the questions because of estimate respectively Content Validity Index (CVI) and Content Validity Ratio (CVR) in this study. For this purpose, the necessity of the questions was evaluated using a scale of three-point ranking, which is as follows: (i) not necessary, (ii) effective, but not necessary, and (iii) necessary. Conformity with the panel’ evaluation, a Content Validity, Reliability (CVR) for all of the scales was calculated. As for Lawshe, if more than half of the panelists represent that each item is necessary, that question has a minimum of content validity [31]. In this study, the CVR for all of the Criteria was 0.82, informing a satisfying outcome. The correlation of the questions was also evaluated, exerting a four-point of rating criteria: (i) no relevant, (ii) insignificancy relevant, (iii) relevant, and (iv) reliable relevant. The Content Validity Ratio (CVI) of every item is the ratio of specialists who measure it from 3 or 4 [32]. In this regard, Polite and Beck presented 0.80 for the allowable lower range of CVI value [33]. An appropriate level of the accordance was determined (CVI = 0.91) between panelists proposing that the measure of scale had a well content validity. Finally, the mean of questions for the perceptional factor was 3.22 (SD¼.33, N¼5), for the nurture factor was 4.3 (SD¼.47, N¼4) and for enabling factor was 4.3 (SD¼.47, N¼4). All of the questions were deleted because of low grading on one of these implications.
Study of statistical analysis
A cross-validation development was exerted in that group (n =400) was randomized. Data obtained from this group were employed of the scales in psychometric test development in this study. After that, the factor analysis was used to sample these dichotomous questions into scales [34]. Every factor analyses used principal components with varimax rotation. In this regard, in the scree plot, the analysis of values was employed to help assign the number of factors to preserve in a specified instrument [35]. In this context, if more than one of the factors transpired, factor analyses compressing 1, 2, and 3 factors were administered for subsequent evaluation of adequate. A question was specified to a factor when its loading was minimum 0.35, and this had no loadings at 0.30 or upper on other factors. Scores on the questionnaire scale were produced by calculating the scores of questions creating that factor. Cronbach’s α was used to evaluate internal consistency in the study [36]. Finally, the test-retest reliability was specified using Pearson correlations.
Validity
Construct validity
The different dimensions of the criterion were specified by implementing exploratory factor analysis (EFA) to apply the oblique rotation and original fundamental factoring. As the correlation between factors was less than 0.3, varimax rotation with Kaiser Normalization was chosen [37]. Because of assessment, sampling efficiency to carry out the satisfactory factor analysis, Kaiser-Meyer Olkin (KMO) Measure of Sampling Adequacy (MSA) for factor analysis and Bartlett's test was accounted for. To specify the supreme construction, the specific value more significant than one and factor loading equivalent to or larger than 0.4 were used [38].
Convergent validity
Validity of convergent was determined to implement correlations of item-scale that reformed for overlaps. In this part, the correlations were computed, applying a Pearson's correlation coefficient. It was anticipated that scores of the item would correlate greater with a specific assumed scale than other scales. The values of correlation of 0.40 or higher were investigated satisfying (r ≥ 0.81-1 as supreme and excellent, 0.61-0.80 very good, 0.41-0.60 good, 0.21-0.40 fair, and 00-0.20 poor) [39].
Reliability
Test-retest
In this study, the test-retest reliability test was evaluated by an intraclass correlation coefficient (ICC). The criterion was re-managed to 45 parsons one month since the first supplementation. The following classification was chosen to construe the compromise levels: 00-0.2 as low, 0.21-0.40 as fair, 0.41-0.60 as moderate, 0.61-0.80 as significant, and 0.81-1 as nearly complete and perfect [39].
Internal consistency
In this study, the internal consistency (IC) of PA2Q-PW accounted for by calculating Cronbachs’ alpha coefficient. The alpha amount of 0.70 or higher was noticed satisfactory [39].
Scoring
The last version of the PA2Q-PW is present. Additional information about this questionnaire and the type of scoring is also available. Nevertheless, in brief scoring, each of these items is from 5 to 1 to create row scores. Like, two of these items on nurtures problem, and susceptibility of doing exercise, and others concerning one’s stimulus were nugatory pointed, scoring toward those items (items 28, in the first version and 31 in the last version) was converted.
Ethical considerations
The Ethics Committee approved the study of Tarbiat Modares University. All of the pregnant women, as participants, confirmed their permission by signing an aware consent form.
Consent to participate
To participate in the human survey, all the pregnant women's written satisfaction was taken, and each time they wished to withdraw from the study with their consent. All of the records data in this study were preserved private in the match with organizational policies on topic solitude. The researcher and other site staff will not utilize such records and information for any target other than operating the survey. In terms of confidentiality, pregnant women and their husbands were told at the beginning of each assessment that their responses are confidential and that they will not have access to each other's answers.
Consent for publication
The consequence of this trial will be broadcasted through peer that reviewed journal articles, introductions at newsletters about pregnant women, and international conferences to be held. All participants gave informed written consent.