Development and Validation of a Chinese Parental Health Literacy Questionnaire for Caregivers of Children from 0 to 3 Years Old

Background Given the limited information on parental health literacy measurements, the study aimed to develop and validate the Chinese Parental Health Literacy Questionnaire for caregivers of children under three years old. Methods We conducted a validity and reliability study through a cross-sectional survey and test-retest analysis respectively between March and April 2017. 807 caregivers of children under three years old were recruited, among which 101 caregivers completed the test-retest assessment with two weeks interval. The reliability was determined by internal consistency, spilt-half reliability and test-retest reliability. The construct validity was assessed by confirmatory factor analysis. The 39-question Chinese Parental Health Literacy Questionnaire was shown with high internal consistency (Cronbach’s α=0.89), spilt-half reliability (Spearman-Brown coefficient=0.92) and test-retest reliability (Pearson correlation coefficient=0.82). The confirmatory factor analysis showed that the construct of the questionnaire fitted well with the hypothetical model. The participants’ test scores of the Chinese Parental Health Literacy Questionnaire in a cross-sectional survey were positively associated with caregivers being mothers, more educated, of children with Shanghai Hukou, having only one child in the family, having higher family income. The Chinese Parental Health Literacy Questionnaire demonstrated good reliability and validity, which could potentially be used as an effective evaluation instrument to assess parental health literacy.


Background
Improving child health is core to the Sustainable Development Goals [1]. In the past decades, the survival rate of children under five years old has improved significantly globally. In low-and middle-income countries, however, there were 250 million children under five years old at risk of not achieving their developmental potential [2]. Early child development largely depends on the quality of nurturing and care provided to the children in the family. Studies have showed that inappropriate caring practice was adversely associated with child development and health [3].
Health literacy is a better predictor of health condition than income, employment, education, race or ethnicity [4]. In China, the 2016 health literacy surveillance reported that only 11.58% Chinese residents had basic health literacy [5]. Caregivers with lower health literacy had difficulty in comprehending important aspects of pediatric anticipatory guidance, including coping with common family emergencies, weighing risks and benefits of routine vaccinations, and conducting home safety checks [6]. Children whose parents had low health literacy often had poor health outcomes, such as asthma control, glycemic control, especially for younger children [7,8]. Low health literacy in parents was also associated with a variety of adverse health behaviors, including not practicing breastfeeding [9], poor performance of taking medicine prescribed [10,11], which could have an adverse effect on children's health.
Currently, there are several scales to access adult health literacy, such as Test of Functional Health Literacy in Adults (TOFHLA) [8], Rapid Estimate of Adult Literacy in Medicine (REALM) [12] and Newest Vital Sign (NVS) [13]. However, other than the Parental Health Literacy Activities Test (PHLAT) [6], no instrument has been specifically developed targeting at evaluating parental health literacy of caregivers with young children. PHLAT, however, was designed for parents with children younger than 13 months and mainly assesses parents' literacy and numeracy skills in understanding instructions of caring for children [6]. .
In 2012, World Health Organization Regional Office for Europe developed a broader and inclusive definition of health literacy, "people's knowledge, motivation and competences to access, understand, appraise, and apply health information in order to make judgments and take decisions in everyday life concerning healthcare, disease prevention and health promotion to maintain or improve quality of life during the life course" [4,14]. This suggests that the measurement of health literacy should be multi-dimensional.
Given the limited information on parental health literacy measurements, our study aimed to develop a Chinese parental health literacy questionnaire for caregivers of children from 0 to 3 years old.

Instrument Development
The development of the Chinese Parental Health Literacy Questionnaire (CPHLQ) comprised three stages as illustrated in Fig. 1.

Stage 1: conceptual framework and indicator generation
The CPHLQ was based on the conceptual framework developed by Sorenson et al. in 2012, operationalized with a 3×4 matrix, including three health domains (health care, disease prevention, and health promotion) and four factors of information processing (accessing, understanding, appraising, and applying) for each domain [14].
Indicators were generated through three steps. Firstly, 10 key topics about children's physical development in three health domains were extracted from literature review and confirmed by a 20-expert consultation (Table 1). Secondly, several indicators were developed based on the 10 key topics and four factors of information processing. Thirdly, a two-round Delphi consultation was conducted with 14 experts to confirm content representativeness, health literacy relevance, feasibility and significance of these indicators. Finally 34 parental health literacy indicators were identified by consensus [15].

Stage 2: questionnaire development
Equivalent questions were designed based on 34 indicators. Among them, 29 indicators were directly transferred into one question; for other five indicators, one indicator was divided into two to four questions. Therefore a 41-question CPHLQ were constructed. Each question reflecting "accessing", "appraising", or "applying" were rated with a 4-point Likert scale, similar to the practice of Sorensen et al. [16]. Meanwhile, questions relevant to "understanding" were mainly in the form of true/false questions or multiple choices with four options, which were designed to test the knowledge level among caregivers. For true/false questions, the correct answer would score 4 points. For multiple choice questions there were 4 options in a question, each option was a true/false question, and one correct choice was worthy of 1 point. Besides, each question had an option "I don't know" which would get a 'zero' score. Each question had a total score ranging from 0 to 4.
Examples of the questions in the CPHLQ are showed in Table 2.
The original version of 41-question CPHLQ was reviewed by one researcher, two child care doctors, two nurses to assess whether the questions consistent to the indicators. The original version questionnaire was piloted with 10 parents to identify any ambiguous or unclear questions and to revise the wording. Minor changes were made to enhance clarity and comprehension.

Stage 3: Pretest
The adjusted original version 41-question questionnaire was administered to a convenient sample of 101 caregivers with children under 3 years old. The pretest was performed to conduct an in-depth Classical Test Theory psychometric analysis of question performance [17]. The question performance is determined by item difficulty and item discrimination.
Item difficulty is the average score on that question divided by the highest points in our study it was 4, and the higher the value, the easier the question [18]. Item discrimination is examined using the question-total correlation [19]. A question is considered to be deleted, when: a) item difficulty lower than 0.2 or higher than 0.8 [20,21]; and b) the coefficient of question-total correlation lower than 0.3 [19]. The results were shown in Additional file 1. Three questions met all screening criteria, e.g. the following: "See the

Participants and data collection
A cross-sectional survey was conducted in 24 community health centers (CHCs) from eight districts in Shanghai. The target participants were the primary caregivers (including parents, grandparents and other caregivers, like nanny) with children under three years old. The inclusion criteria were as follows: a) above grade three primary educations, b) able to communicate verbally or literally with the investigators; c) willing to participate in.
In Shanghai, the routine child health care is provided by CHCs. Therefore, in each participating district, three CHCs were selected as the study sites, representing high, medium and low social economic status (based on local economic indicators and child health care management rates). Before the survey, child healthcare doctors in the selected CHCs as investigators were trained about how to recruit participants and complete the self-administered questionnaire.
The caregivers coming to the CHCs between March and April 2017 and meeting the inclusion criteria were invited to join in the survey by trained doctors. 1090 caregivers were approached, and 807 (74.0%) caregivers participated in the study. Among these participants, 101 (12.5%) caregivers were asked to complete the questionnaire again two weeks later to assess test-retest reliability. Data on demographics were also collected from the participants, including caregiver's relationship with the child, education level, family income, child's age, gender, and Hukou (the Chinese official residency registration by location, which is directly linked to social costs, social benefits and administration), etc.

Data Analysis
Several psychometric properties of the CPHLQ and three subscales were assessed.
Internal consistency was measured with Cronbach's α [22]. Spilt-half reliability was measured with Spearman-Brown coefficient between odd questions and even questions [22]. Test-retest reliability was measured with the Pearson correlation coefficient between the CPHLQ results completed by 101 caregivers before and after [22]. In addition, the reliability analysis of three subscales was also performed. Values greater than 0.70 indicated acceptable reliability [23,24]. The floor or ceiling effects were assessed by the proportion of respondents who got the lowest or the highest score [25].
Given that hypothesized constructs were identified with a priori, confirmatory factor analysis (CFA) was used to verify the construct validity [26]. The analysis was conducted separately for the three subscales of HC-HL, DP-HL and HP-HL, in which questions were loaded into four factors related to four information-processing domains of accessing, understanding, appraising and applying. CFA was conducted with maximum likelihood estimation by using AMOS 21.0. The model fit was considered 'relatively good' if the following criteria were met: root mean square error of approximation (RMSEA) lower than 0.08; goodness-of-fit index (GFI) greater than 0.90; adjusted goodness-of-fit index (AGFI) greater than 0.90; comparative fit index (CFI) greater than 0.90; and due to the large sample, c 2 /df lower than 5 [27,28].
The final version of the CPHLQ consisted of 39 questions. When calculating the scores for parental health literacy, the weight of each indicator was equally allocated to the questions under it based on the significance assessed during Delphi consultation. The total score was transferred to percentage grading system with the full score of 100. A higher score indicated that the caregiver had higher health literacy. The mean and standard deviation (SD) of CPHLQ score were calculated. Additionally, descriptive statistics of the participants' characteristics were tabulated. The relationships between scores and demographic characteristics were assessed with either a t-test or a one-way ANOVA.

Results
Results of the cross-sectional survey for the validation of the CPHLQ are presented below.

Social and demographic characteristics of participants
In total, 807 caregiver-child pairs participated in the study. There were 551 mothers (68.3%), 178 fathers (22.1%) and 78 grandparents or other caregivers (9.6%). The social and demographic characteristics of the caregivers and their children are shown in Table 3. 64.9% caregivers had college or above education. Among the participants' children, 52.0% were boys, 67.0% were registered as Shanghai Hukou; and 70.5 % were the only-child.
70.5% participants reported to have a family monthly income of over RMB 4,500 (USD 678), which was the disposable monthly income per capita in Shanghai in 2016 (Table 3)

Reliability
The overall 39-question CPHLQ had high internal consistency (Cronbach'

Content validity
In this study, we used several methods to ensure the content validity of the questionnaire.
We applied the health literacy integration conceptual framework in 2012 by Sorenson et al to construct the CPHLQ and to define the dimensions of health literacy in this study.
Through literature review and expert consultation, it was ensured that the CPHLQ covered the key content of the physical development of children from 0 to 3 years old. Delphi consultation was carried out to establish the indicators of health literacy of caregivers with children from 0 to 3 years old. Questions were generated on the basis of expert consultation and pilot testing.

Construct validity
Construct validity was assessed by CFA. Based on the hypothesized constructs, CFA was conducted separately. The results showed a relative good fit of the four-factor structure within three domains of parental health literacy (Table 4).

Descriptive statistics for the CPHLQ
The CPHLQ score of this sample of caregivers with children under 3 years old ranged from 6.0 to 96.8, with a mean score of 72.8 ± 12.5. No floor or ceiling effects was found. Table 3, mothers had a higher CPHLQ total score than fathers and grandparents or other caregivers (P .001).The caregivers with a higher CPHLQ total score had higher education level (P .001) and higher family income (P .001). In addition, caregivers of children with Shanghai Hukou ( P .001) and of single child (P=0.004) had a higher CPHLQ total score. Scores of the CPHLQ were not significantly associated with child's age (P=0.659) and gender (P=0.384).

Discussion
The 39-question CPHLQ was developed for evaluating parental health literacy among caregivers of children from 0 to 3 years old in Shanghai. The CPHLQ score range is between 0 and 100, a higher score indicates higher parental health literacy level.
Psychometric analysis results indicated that the CPHLQ has good reliability and validity, and it could be a useful instrument for assessing parental health literacy for whose caring for children aged under 3 years in the Chinese context.
Nutbeam suggested that the measurement of health literacy would be best achieved where content and context were well defined [29]. This study was based on the conceptual framework of health literacy [14], which integrated the content of medical services and public health, and emphasized the individual's comprehensive literacy abilities, including functional, interactive, and critical health literacy. Applying this conceptual framework will provide a better clarify for the connotation of health literacy, and it provides a theoretical basis for questionnaire development. This study determined the key topics about children's physical health through literature review and expert panel discussions, ensuring the content were well-adapted to the caregivers with children under 3 years old in the Chinese context. In the CPHLQ, we used a 4-point Likert scale to determine the ability of "accessing", "appraising", and "applying" health information, and used true/false questions or multiple choice to assess the "understanding" of the health information among caregivers. A systematic review showed that this mixed measurement approaches offers advantages by broadening the health literacy concept and enabling researches to address multiple skills [30].
Psychometric evaluation of the CPHLQ produced plausible results. The overall 39-question questionnaire was reliable, demonstrated by high internal consistency, spilt-half reliability and test-retest reliability (the coefficients were all over 0.8). For these three subscales, all reliability coefficients were over 0.6 which was considered as acceptable reliability for subscales [31]. The results of confirmatory factor analysis showed that the construct of the questionnaire fitted well with the theoretical model. Despite comparative fit index (CFI) was below the recommended criteria of 0.90 in HP-HL, it still represented a tolerable fit [32,33]. In addition, strict content development procedures were employed during the questionnaire development process [34], leading to the good content validity.
The study found that mothers' parental health literacy was significantly higher than fathers, grandparents and other caregivers. One explanation could be that in Chinese fathers are less involved in caring for children despite the vital role of fathers in child development [35]. In line with other studies, our study found that lower health literacy was significantly associated with lower education level and lower family income [36,37].
We also found caregivers whose children had Shanghai Hukou scored higher than those whose children did not have Shanghai Hukou. This is consistent with findings from another study that the level of health literacy among Shanghai residents was higher than the average of the country [38]. This might be partially due to relative higher education level of Shanghai residency and the health care resources, e.g. health promotion and health information are more accessible among Shanghai registered family [39]. Another interesting finding was that caregivers with two or more children had lower parental health literacy than caregivers with only one child. This indicated that the caregivers with only one child might pay more attention on child nurturing.
The development and validation of an appropriate instrument is an essential step for parental health literacy research. To our knowledge, this is the first study of developing and evaluating a parental health literacy questionnaire for caregivers of children from 0 to 3 years old in China. Using the CPHLQ in a larger and representative sample to determine cutoff point is needed. The instrument could be potentially used in other Chinese population and adapted for the use in other places of the world. Furthermore, the CPHLQ can help to identify the population in need of parenting and child care related information.
Therefore, it will be useful for developing targeted interventions to improve the parental health literacy of caregivers with children from 0 to 3 years old and quality of care.

Consent for publication
Not applicable.

Availability of data and materials
The raw dataset analyzed in the current study are available from the corresponding author on reasonable request.

Competing Interests
The authors declare that they have no conflict of interests.

Funding
The study was funded by grant GWIV-31 from Shanghai Municipal Health Commission.

Author contributions
YZ participated in study design, conducted data acquisition, analysis and interpretation, drafted the initial manuscript, and reviewed and revised the manuscript; HJ conceptualized and designed the study, draft and revised the manuscript; ML, BX and SA critically reviewed the manuscript for important intellectual content; HS and XQ conceptualized the study and reviewed and revised the manuscript; and all authors approved the final manuscript as submitted.   a Four-factor model of each domain included accessing, understanding, appraising, and applying health information.
HC-HL, health care health literacy; DP-HL, disease prevention health literacy; HP-HL, health promotion health literacy.
RMSEA, root mean square error of approximation; GFI, goodness-of-fit index; AGFI, adjusted goodness-of-fit index; CFI, comparative fit index. Additional file 1.pdf