Hypertension doctors’ awareness and practice of medication adherence in hypertensive patients: a questionnaire-based survey

Study design

The survey was completed between May 1, 2022 and July 1, 2022 in Hunan province, China. The questionnaire was filled out via Questionnaire Star (https://www.wjx.cn). If conceptual issues such as external interventions, patient factors, socioeconomic factors, medical factors, and policy factors were involved, a brief explanation of these concepts were provided after the question. All participants can only complete the questionnaire once. CHQC members were contacted to answer an initial online screening questionnaire. Those who met the inclusion criteria were immediately invited to participate in the main online survey.

Inclusion criteria

All members of the Hunan CHQC were selected for this cross-sectional survey. Only those hypertension doctors who had seen hypertensive patients on long-term medication were included in this study. However, hypertension doctors engaged in studies related to medication adherence were excluded from the study. According to the evaluation standards of China’ tertiary hospitals (National Health Commission of the People’s Republic of China, Medical Administration Department, 2022), Chinese hospitals are organized into a 3-tier system to reflect their abilities in healthcare, medical education, and medical research. Distinguished by the number of beds, hospitals are designated as primary (I class, <100 beds), secondary (II class, 100–500 beds), and tertiary institutions (III class, >500 beds). Further, each tier is further subdivided into three subsidiary levels: A, B, and C based on service level, size, medical technology, medical equipment, management level, and medical quality. In this study, the respondents/CHQC members were from different levels of hospitals. As a rule of thumb, overfitting is least possible to occur if the number of samples is 10 times or more the number of independent predictors (Concato, Feinstein & Holford, 1993). Since the items used in the study consist of 10 items each for awareness-related scales and practice-related scales, the sample size for this study should be greater than 100.

Data collection

First, to build the initial item pool, we used the keywords “hypertension/doctor/medication adherence/awareness/practice” to search five English databases (PubMed, Embase, the Cochrane Library, EBSCO, and Web of Science) and four Chinese databases (Chinese Biomedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), Wanfang Data, and VIP Information). After reading the relevant literature, a questionnaire item pool was formed, which mainly included two dimensions and 40 items.

Then, the questionnaire items were determined according to the results of expert consultation. The inclusion criteria for selecting experts were as follows: (1) Familiar with doctors’ awareness and practice of medication adherence in hypertensive patients; (2) fully understand the questionnaire preparation method and process; and (3) hold a title of deputy director or above. Finally, eight experts were selected to form an expert group, including three chief physicians, three deputy chief physicians, and two directors. They had expertise in cardiology or public administration. Basic information of these experts: three males, five females, aged 35–55 years old, and work experience ≥10 years. They all received a doctor’s degree. Two rounds of expert consultation were conducted. The first round was to screen the items of the questionnaire. The items of expert concern were selectively modified, merged, or deleted. The experts could add, remove, or modify the items. The second round was mainly based on the feedback from the results of the first round of expert consultation to modify the items and formulate the questionnaire again. In the end, 10 out of 40 items were excluded. This resulted in an initial version of the questionnaire consisting of two topics and 30 items, 24 of which were scored using the Likert scale.

Next, we calculated the correlations between individual items and total scale scores of the initial version. Items with an item-total correlation coefficient of less than 0.35 were excluded (Liu et al., 2022). After that, the scale retained 20 items, including 10 items of awareness (three questions) and 10 items of practice (four questions), with scores of 5, 4, 3, 2, and 1 based on the 5-point Likert scale. These scores were aggregated to obtain an overall awareness or practice score from 10 to 50, with higher scores reflecting higher levels of awareness or practice. The final questionnaire was divided into four parts (Table S1): demographic information, 10 items of awareness (three questions, Table S2), 10 items of practice (four questions, Table S3) and six items that were not scored on the Likert scale. All the statements are correct. The questionnaire didn’t have previously been published elsewhere.

After that, a pre-survey was conducted to further ask advice on the appropriateness of the content and format of the items so that all items are easily understandable. To this end, 100 hypertension doctors were recruited from Changsha, Hunan. They read the whole questionnaire and were asked to recount the meaning of each item. All items in the questionnaire were retained because they had appropriate statements. Cronbach’s alpha for awareness-related scales was 0.764 and Cronbach’s alpha for practice-related scales was 0.836, indicating the questionnaire has good reliability.

Finally, in our formal survey, the questionnaire had high reliability, with Cronbach’s alpha coefficients of 0.916 and 0.911 for the awareness-related and practice-related scales, respectively.

Data analysis

Statistical analysis was performed using IBM SPSS version 24.0 (SPSS Inc., Chicago, IL, USA). Categorical variables were evaluated using frequencies and percentages; continuous variables were evaluated using mean and standard deviation. Age and work experience categories were analyzed by calculating lower and higher quartile values. The Kolmogorov–Smirnov test was performed to check data normality. Missing data was not analyzed.

Univariate analysis was performed using the chi-square test or spearman’s correlation coefficient, a nonparametric test for comparing unequal variances. Multivariate analysis was performed using a generalized linear model due to non-normally distributed data. Correlation analyses were performed to preselect the covariates to be used and to avoid those that would result in multicollinearity within the same model, and age and work experience were found to be collinear variables. In the multivariate analysis, we included the variables that were statistically significant different in the univariate analysis and all factors that may affect the dependent variables (other than age).

Spearman’s correlation coefficient were used to analyze the correlation between awareness scores and practice scores. A difference was considered statistically significant at p < 0.05.

Institutional review board statement

This study was conducted in accordance with the Declaration of Helsinki and was approved by the Ethics Review Committee of the Third Xiangya Hospital of Central South University (No. I22078). Participants received an informed consent reminder prior to the start of the questionnaire, stating that continuing to answer the questionnaire implies informed consent.

Demographic characteristics

A total of 321 hypertension doctors were contacted via E-mail, and 251 (78.19%) responded and completed their questionnaires. Due to incomplete information, we excluded 15 questionnaires and finally included 236 (73.5%) valid questionnaires for analysis (Table 1). A total of 64.4% of respondents were females. Approximately half of the respondents were 40 years old or above and had over 14 years of work experience. Most (87.7%) did not have hypertension, but 54.2% of them had a family history of hypertension. These respondents included 104 chief physicians.

The awareness of medication adherence

Only 49.2% of respondents completely knew the definition of medication adherence. Besides, approximately 3.8–26.7% of physicians reported that they had received relevant training on medication adherence through various means such as academic literature, online academic conferences, onsite lectures and peer discussions, hypertension research, and refresher training. Generally, these participating hypertension doctors showed insufficient understanding of medication adherence evaluation tools, with a complete comprehension rate of 5.9–8.1% (Table 2).

The average awareness score of the total study subjects was 29.8 ± 8.8. Univariate analysis revealed significant differences in the awareness scores of hypertension doctors of different ages, work experience, education and training, hospital levels, professional ranks, history of hypertension, family history of hypertension, number of consulting for hypertension per week, and number of antihypertensive prescriptions issued per week (ps < 0.05) (Table S4). Further multivariate analysis showed that respondents with higher educational level and professional rank had higher awareness. Moreover, respondents with more consultations and antihypertensive prescriptions issued had higher awareness (ps < 0.05) (Table 3).

Regarding the percentage of patient medication adherence, 41.1% of respondents selected approximately half of patients had good medication adherence and only 5.5% of respondents selected >80% patients had good medication adherence. When asked to explain poor medication adherence in detail, 75.4% of respondents selected all of the conditions listed, including not taking medication on time, unauthorized dosage changes, and unauthorized changes in dosing frequency. Regarding the understanding of the factors affecting medication adherence, only 41.1% of respondents answered that medical factors were very important, while most (75.1%) considered patient factors to be very important. In addition, 31.4% and 29.2% of respondents rated socioeconomic and policy factors, respectively, as very important. When asked which clinicians were primarily responsible for patient medication adherence, specialists, general practitioners, and nurses accounted for 21.2%, 67.4%, and 3.4%, respectively. Nevertheless, 72.5% of respondents agreed that medication adherence can be improved through external interventions (Table 4).

The practice of medication adherence

Nearly 60.0% of respondents said they had been emphasizing the importance of medication adherence, while approximately 25% of them had been evaluating the medication adherence of hypertensive patients. The interventions always used by respondents to improve medication adherence include: “Answering the patients’ questions” (35.2%), “Emphasis on the role of medication” (52.1%), “Requirements for regular outpatient follow-up” (51.7%), and “Requirements for accompanying/family members to observe the patient’s medication” (41.1%). Only a small portion of respondents always used apps (20.3%), video, and audio materials (14.8%) to educate hypertensive patients. Furthermore, 33.5% of respondents always took the regimen of minimizing the number of doses. In addition, 78.8% of the respondents always or frequently took the individual differences of patients into account when intervening in medication adherence (Table 5).

The average practice score of the respondents was 39.4 ± 7.1. Univariate analysis found significant differences in the practice scores of hypertension doctors with different ages, work experience, education and training, hospital levels, professional ranks, history of hypertension, family history of hypertension, number of consulting for hypertension per week, and number of antihypertensive prescriptions issued per week (ps < 0.05) (Table S5). Multivariate analysis showed that respondents with more consultations for hypertension and antihypertensive prescriptions issued had better practice (ps < 0.05). Also, respondents with 6–13 years of work experience had better practice than those with less than 5 years of work experience (p = 0.017) (Table 6).

Next, we investigated potential obstacles to improving medication adherence in hypertensive patients. The results showed that “heavy clinical work” (84.3%) and “poor doctor-patient communication” (71.2%) were the two main obstacles. Additionally, 64.0% of the respondents indicated that the lack of cooperation between hypertension doctors and patients was the main resistance to improving medication adherence (Fig. 1).

Relevance of medication adherence awareness and practice

Finally, we analyzed the correlation between awareness scores and practice scores using the Spearman correlation coefficient and found a strong positive correlation between hypertension doctors’ awareness and practice in terms of patient medication adherence (R = 0.682, p < 0.001), suggesting that the higher their awareness, the better their practice (Fig. 2).