Study setting and population
This cross-sectional survey was conducted from 19 provinces during January-March 2018 in China. The inclusion criteria for the survey participants were 1) aged 30 years or older at the interview; 2) able to give consent to participate in the study, and 3) capable of understanding and answering the questions. The participants were identified and interviewed face-to-face by medical students in Jilin University (Enrolment year: 2017; Specialty: Preventive Medicine) using a structured questionnaire. The participants for this survey included the relatives, friends, and neighbours of the students. Before conducting the survey, all medical students were trained to identify suitable participants and conducting the survey with a structured questionnaire in a face-to-face meeting room by related researchers. This study was approved by the Ethical Committee Board at the School of Public Health, Jilin University. Each participant also provided written informed consent to this study.
Socio-demographics (sex, age, body weight, height, residence, education level, and family annual income), lifestyle information (smoking, alcohol use), prior fracture and prior bone mineral density test were collected using a structured questionnaire. Height and weight were self-reported. Body mass index (BMI) was calculated as body weight (kg) divided by squaring of body height (m2). Educational level was classified as primary and below (Years of education: 6 and below), junior (Years of education: 7-9), senior (Years of education: 10-12) and undergraduate and postgraduate educations (Years of education: 13 and above). A residence was classified as urban, rural and suburban.
We assessed osteoporosis awareness level using the following domains, including by definition, diagnosis, signs/symptoms, treatment, complications, prognosis, causes, risk factors, and prevention of osteoporosis; the questionnaire about osteoporosis awareness was the same as previously published research . The reliability and validity of the questionnaire was tested among 30 Chinese subjects before the formal survey. This questionnaire had good internal consistency (Cronbach’s α = 0.746). Under the factorial validity test, the related components explained a cumulative 60% of the variance in the awareness scores. The Kaiser-Meyer-Olkin measure of sampling adequacy and Bartlett’s test of sphericity both showed that the results were suitable for factor analysis. Besides the osteoporosis awareness questions, we also collected the sources of the participants acquiring their existing osteoporosis knowledge (e.g., newspapers and magazines, advertising leaflets, television or radio health program).
We used descriptive statistics to describe the characteristics of the study population and the main variables. Continuous variables were shown as mean ± standard deviation (SD); categorical variables were shown as percentages.
Awareness scores were created by assigning a “1” to each correct response and a “0” to each incorrect or “unsure” response. Awareness scores for all questions were summed for a possible range of 0 to 29; higher scores suggest greater awareness. The domain scores were an average of the percentages of correct answers to all questions under each domain.
To test the relationship between risk factors and overall awareness scores, we used multiple linear regression models. Covariates included sex, age, body mass index, residence, educational level, family annual income, prior bone mineral density test, prior fracture, smoking, and alcohol use.
All statistical analyses were performed by using SPSS software (version: 25.0; SPSS Inc, Chicago, IL).