2.1 Instrument development
2.1.1 Items generation
Cox's Interaction Model of Client Health Behavior (IMCHB) was used to design the item content of postoperative visual function rehabilitation compliance assessment tool for children with congenital cataract, so as to achieve the coverage of compliance by children, caregivers and medical staff. And make it applicable to the nursing of congenital cataract. The treatment compliance of children is affected by the uniqueness of children and the interaction between patients and health educators(Cox, 2003). The uniqueness of children is affected by background elements, intrinsic motivation, cognitive evaluation, and emotional response. Combined with the characteristics of postoperative visual function rehabilitation in children with congenital cataract, five dimensions of the postoperative visual function rehabilitation compliance scale for children with congenital cataract were preliminarily formulated, which were: ① Background factors: family and social factors, environmental resources; ② Intrinsic motivation: patients can feel their own ability and autonomy, and provide them with self-rewards; ③ Cognitive evaluation: patients' perception of their own health status and influencing health behaviors; ④ Emotional response: the emotional experience that affects health behaviors and can hinder or promote cognitive activities; ⑤ Doctor-patient interaction: medical staff provide help with health-related information, professional skills, emotional support and decision control according to the characteristics of children(Cho et al., 2023; Shen et al., 2021; Wei, 2022).
"congenital cataract /pediatric cataract /infant /children / pediatrics /visual function rehabilitation /refractive correction /occlusion treatment /amblyopia training /questionnaire /measurement /assessment /scale development /scale customization /scale development /reliability /validity" were used as search terms. CNKI, Wanfang, SinoMed, PubMed, Embase, and Web of Science were searched from the establishment of the database to February 2022. Related literature was read and collected, and a scale pool containing 30 items was initially developed based on Cox's Interaction Model of Client Health Behavior.
Using the purposive sampling method and the principle of data saturation, 13 parents of children with congenital cataract who were treated in the ophthalmology clinic and inpatient department of a children's specialized hospital in Guangzhou from February 2022 to April 2022 were selected for semi-structured interviews. Interview Outline: ①How is your child's compliance with visual rehabilitation? What difficulties have you encountered? ②What factors do you think affect your child's compliance? ③What good methods do you have to improve children's compliance with covering treatment? ④What kind of help do you hope to get in the process of helping children with visual function rehabilitation? The research team sorted out and analyzed the interview data, and added 6 items according to the interview content.
2.1.2 The Delphi technique
The inclusion criteria of experts were: ① doctors should have master's degree or above, and nurses should have bachelor's degree or above; ② intermediate or above professional title; ③ Engaged in children's ophthalmology work, nursing management, clinical nursing work, psychology and other fields, with more than 10 years of work experience; ④ interested in this study.
Consultation questionnaire includes three parts: the letter consultation instructions, the questionnaire and the basic information of the experts. The consultation instructions included the research background, purpose and significance, the definition of related concepts, the introduction of Delphi expert consultation and the instructions for filling in. The items and dimensions of the postoperative visual function rehabilitation compliance scale for children with congenital cataract were listed in the text of the questionnaire. Likert5 scale method was used to evaluate the items and dimensions, which were assigned 1~5 points from "Not important" to "Very important". Content validity was evaluated at the same time. Likert3 scale method was used to evaluate the applicability of each item and dimension, which was assigned 1~3 points from "Not applicable" to "Applicable". Experts were asked to explain why they chose not to apply or apply after modification. The basic information of experts included education background, professional title, research field, and working years. Experts self-rated their familiarity with this research question from four aspects: event experience, theoretical analysis, reference to domestic and foreign literature, and intuitive sense.
From April 2022 to June 2022, 15 experts were selected to evaluate the items of the scale. The researchers introduced the purpose, significance, theoretical basis and research methods of this study to experts in detail, and communicated with experts by telephone, WeChat or email to make experts fully understand and pay attention to this study. After two rounds of consultation, the experts' opinions tended to be consistent, and the consultation was finished. The items of the scale were supplemented, deleted and modified according to the criterion of importance assignment mean ≥3.5 and coefficient of variation ≤0.25(Cheon et al., 2022). According to the results of expert consultation, the items were revised and supplemented to form the first draft of the postoperative visual function rehabilitation compliance scale for children with congenital cataract. In the first round of consultation, 2 items were deleted, 3 items were modified, and 1 item was deleted. In the second round of consultation, no item was modified. There were 32 items in the revised scale.
2.1.3 Face validity test
Convenience sampling was used to select 30(Younas & Porr, 2018) parents of children with congenital cataract who were treated in the Ophthalmology clinic of a children's hospital in Guangzhou for a pre-survey to evaluate the readability and operability of the scale items in June 2022. Thirty questionnaires were distributed and collected on the spot. The time of 30 caregivers to complete the pre-survey scale was (13.46±8.68) minutes, and 2 items were modified according to the feedback. Inclusion criteria: ① Children with lens opacity at birth or within the first year of life who met the diagnostic criteria of congenital cataract in the 7th edition of Zhufusang Practical Pediatrics; ② children ≤15 years old who need visual rehabilitation training after surgery; ③ The parents of the children agreed to rehabilitation after surgery and signed an informed consent. Exclusion criteria: ① Combined with mental disease, dementia, disturbance of consciousness, etc.; ② Complicated with serious infection and malignant tumor; ③ Retinopathy of prematurity, endophthalmitis, outer exudative retinitis, retinoblastoma and other causes of amblyopia requiring visual function rehabilitation; ④ Incomplete clinical and follow-up data.
2.2 Psychometric tests
2.2.1 Study participants
The parents of children with congenital cataract who visited the outpatient and inpatient department of a children's hospital in Guangzhou from July 2022 to July 2023 were selected as the survey objects by the convenient sampling method. The inclusion and exclusion criteria were consistent with those of the pre-survey. According to the calculation method of sample size, the sample size of factor analysis should be 5-10 times of the number of items in the scale, and the sample size required for factor analysis should be more than 200 cases(Seo & Song, 2021; Younas & Porr, 2018). The first draft of the scale had 32 items, and considering 10% inefficiency, the sample size was 225 cases. This study has been approved by the Ethics Committee (2022209A01).
2.2.2. Data collection
The general information questionnaire was designed by the research team on the basis of referring to the relevant literature, including the gender, age, type of cataract, complications, age and gender of parents.
The initial version of the Postoperative Visual Rehabilitation Compliance scale for Children with Congenital cataract included 5 dimensions and a total of 32 items. Each item was scored by Likert 5-point scale, and "Completely inconsistent" was scored by 1 point, "Less consistent" was scored by 2 points, "Generally consistent" was scored by 3 points, "More consistent" was scored by 4 points, "Completely consistent" was scored by 5 points. Three items including "my child is not willing to accept visual function rehabilitation", "my child has not serious behavior such as stealing and slacking in the visual function rehabilitation", and "it is difficult for me to carry out visual function rehabilitation for my child" were scored in reverse.
The researchers introduced the purpose and significance of this study to the parents in uniform instructions. After obtaining their consent, a questionnaire was filled out on the spot. The questionnaires were filled out with one-to-one guidance from the researchers, and the questionnaires were collected on the spot. If there are any missing items, fill in on the spot to ensure the completeness of the data.
2.2.3 Data analysis
Frequency analysis method, discrete trend method, critical ratio method, correlation coefficient method, Cronbach's α coefficient, commonality and factor load were used to test the discrimination of each item. Item deletion criteria: ① Frequency analysis method: Responses were focused on specific choices (over 80%) or an option was not answered at all to consider removal. ② Discrete trend method: items with standard deviation < 0.75 should be deleted(Kuramochi et al., 2021). ③ Critical ratio method: the scale scores were sorted from small to large, and the corresponding values of 27% and 73% were used as the upper limit value and the lower limit value for dividing the low group and the high group, respectively, to compare whether there was any difference in the scores of each item between the low group and the high group. If there was no difference in the scores of the two groups, the discrimination of the item was poor, and it was considered to delete. ④ Correlation coefficient method: if the correlation coefficient with the total score of the scale was not statistically significant or less than 0.3, it was considered to delete the items(Cheon et al., 2022). ⑤Cronbach's α coefficient: after removing an item, Cronbach's α coefficient increased greatly, so consider deleting it; ⑥commonality and factor load:the items with factor loading value ≥0.4 were retained.
Item-level content validity index (I-CVI) of postoperative visual function rehabilitation compliance scale for children with congenital cataract and scale-level content validity index (S-CVI) . If I-CVI ≥0.70 and S-CVI ≥0.80, the content validity of the scale was good(Cheon et al., 2022).
Exploratory Factor Analysis (EFA) was used to test the construct validity of the scale. In the exploratory factor analysis, the Kaiser-Meyer-Olkin (KMO) index and Bartlett’s sphericity test were applied to confirm that the data were appropriate for factor analysis. The KMO index ranged from 0 to 1, with the closer to 1 indicating a stronger correlation between the variables the more suitable for factor analysis; Principal component analysis (PCA) and maximum variation method were used for orthogonal axis rotation. The common factors with eigenvalues > 1 and cumulative variance contribution rate > 40% were selected, and the items with factor loading value ≥0.4 were retained.
SPSS25.0 statistical software was used for data processing. Measurement data were expressed as (mean ± standard deviation), enumeration data were expressed as numbers ( percentage), and authority coefficient, effective questionnaire recovery rate, Kendall harmony coefficient and coefficient of variation were expressed as authority coefficient of experts, enthusiasm, coordination degree of opinions and moderation degree of opinions, respectively. P < 0.05 was considered statistically significant.
Cronbach's α coefficient and split-half reliability were used to evaluate the internal consistency of the total score and the scores of each dimension of the scale. In the fourth week after the formal investigation, 30 subjects were selected for repeated measurement to evaluate the test-retest reliability of the scale.