DOI: https://doi.org/10.21203/rs.3.rs-2738980/v1
Background & Objectives: High blood pressure is a major cause of cardiovascular disease and premature death worldwide. The importance of self-care in controlling hypertension is obvious, and a valid and reliable tool is needed to assess the self-care status of patients with hypertension. This study aimed to evaluate the psychometric properties of the Persian version of the Blood Pressure Self-Care Level Questionnaire.
Methods: Present methodological study was conducted on 218 patients with hypertension visiting the Clinic of Qom educational and medical centers. Subjects were selected with simple sampling. Data were collected using a self-care behaviors questionnaire, Morisky Medication adherence scale, and a demographic questionnaire. The translation was done from the recommended backward-forward method according to the WHO protocol. Then face and content validity، construct validity were performed (using a comparison of known groups and confirmatory factor analysis). To test reliability, Cronbach's alpha was used. Data analysis was performed by SPSS and smart-PLS software.
Results: The correlation between the scores obtained from the self-care behaviors questionnaire and the Morisky Medication adherence scale confirmed the criterion validity. The factor loadings of the self-care behaviors questionnaire were significant in all structures. The factor loadings were higher than 0.5 except for three expressions. The extent of average variance extracted (except feeding structures) was greater than 0.5 which revealed the convergent validity of the named variables. The divergent validity of the questionnaire was confirmed using the Fornell-Larcker criterion and the heterotrait-monotrait ratio (HTMT). Cronbach's alpha coefficient, combined reliability, and index were optimal.
Conclusion: According to research findings, the Persian version of the questionnaire has good validity and reliability that can be used as a tool to measure the level of self-care of blood pressure by health care providers.
The number of people with high blood pressure increased from 648,000,000 people in 1990 to 1278,000,000 in 2019, and the number of people with high blood pressure is projected to reach 1560,000,000 people 2025 (1). According to studies, the prevalence of hypertension in Iran is 25–48.2% (2, 3). Hypertension is a major cause of cardiovascular disease and premature death worldwide (4). High systolic blood pressure (SBP) was the main risk factor in the DALY (disability-adjusted life years) ranking, accounting for 10.4 million deaths and 218 million DALYs (5). High sodium intake, low potassium intake, obesity, alcohol consumption, physical inactivity and unhealthy diet and genetics are risk factors for high blood pressure (4, 6). Self-care is one of the most effective ways to deal with high blood pressure that helps people with high blood pressure to take more responsibility for their health (7). Self-care includes the steps people take to lead a healthy lifestyle, take care of their chronic illness, and prevent further illness. In hypertension, the self-care behaviors recommended for optimal disease control include: (a) adherence to antihypertensive drugs, (b) following a healthy low-salt diet, (c) engaging in adequate physical activity, (d) quitting smoking and (e) moderating alcohol consumption (8, 9). There is ample evidence that people with high blood pressure have poor adherence to their self-care behaviors (10). For example, despite increasing public awareness and improved access to new drugs, only 30 to 40 percent of patients reported taking their medications regularly (11).
Assessment of self-care behaviors in patients with high blood pressure may reveal important information for health experts to control high blood, but the lack of standard instruments for measuring self-care can be one of the causes of poor self-care among patients with hypertension (12). Morisky Medication Adherence Scale (MMAS-8) is one of the self-care scales in patients with high blood pressure (13), which is not comprehensive and only examines the adherence to the medication regimen. The reliability and validity of this scale was reported acceptable for patients with hypertension in Iranian population (14). Another scale is Hypertension self-care profile (HTN-SCP), the validity and reliability of which has been evaluated in Iran by Ghani Gheshlagh et al. with good validity and reliability, but this scale does not pay attention to the physical activity factor As an important factor in self-care (12).
The H-SCALE is a 31-item scale that developed by Warren-Findlow, and assesses all aspects of self-care in patients with hypertension (15). Some studies have confirmed that the H-SCALE is a valid and reliable scale for the measurement of self-care in patients with high blood pressure living in different cultures and contexts (16, 17). While psychometric evaluation of English and Spanish versions of this scale has been done, due to the importance of self-care in patients with hypertension and the need for localized and comprehensive scales, the aim of this study was to translate and evaluate the psychometric properties of the Persian version of the H-SCALE in patients with high blood pressure in Iran.
The study is of a methodological type that was conducted to translate and evaluate the psychometric properties of the H-SCALE. Participants were patients with hypertension referred to the clinic of Qom educational and medical center, Iran selected through the convenience sampling method. Inclusion criteria were age equal to and over 18 years, diagnosis of hypertension by a cardiologist, no mental or cognitive impairment, at least 6 months after diagnosis of disease, ability to communicate and respond, and consent to participate in the study. A sample size greater than or equal to 100 recommended for validate a scale. Two hundred and eighteen patients were included in the study according to the criteria after obtaining permission from the university Vice Chancellor for Research and coordination with educational and medical centers. Then, the purpose of the project and how to do it was explained to the participants. The questionnaires were completed within 6 months after ensuring the confidentiality of the information with the researcher and obtaining their consent.
To collect data, H-SCALE, The Morisky Medication Adherence Scale (MMAS-8), and demographic and medical information were used:
The H-SCALE questionnaire includes six subscales and 31 questions. First, drug adherence including 3 questions that examine adherence to drug use in the last 7 days. The score of each question is from 0 to 7 and the total score is from 0 to 21 points. A person who gets a score of 21 has a positive attitude. Second, nutrition including 10 questions about healthy eating (low fat and low salt diet, avoiding salt while cooking and eating, and avoiding high salt foods and fruits and vegetables) 7 questions of which should be reversed. The score range of each question is from 0 to 7 and the overall score is from 0 to 70. The positive score for each question is a score of 6 out of 7. That means a high score of 60 is a positive score. Third, physical activity consisting of 2 questions, the score range of each is from 0 to 7 and the overall score range is 0 to 14. Those who score higher than 8 have positive behavior. Fourth, tobacco consisting of 2 questions, the range of each being from 0 to 7 and the overall score is from 0 to 14. Those who choose zero days have a positive attitude.Fifth, weight Management containing 9 questions on 0 to 5 Likert scale (strongly agree to strongly disagree) that measure weight control behaviors in the past month. The score range is from 9 to 45 and the score above 35 is positive in weight management.
The MMAS-8 has seven two-point options and one five-point option (never = zero, rarely = 1, sometimes = 2, often = 3, always = 4 points) and obtaining a score of six or higher represents optimal adherence to treatment. The MMAS-8 was translated into Persian by Ghani Gheshlagh et al. (2015) and its validity and reliability were also confirmed. Demographic and disease information questionnaire included age and sex, level of education, monthly income, housing status, employment status, duration of illness and comorbidiy.
To perform the translation process, the recommended backward-forward method based on the protocol of the International Quality of Life Assessment Project (IQoLAP) was used (18). For this purpose, first, 2 fluent English translators performed 2 separate translations of the English version of the questionnaire into Persian. The original Persian version of the above two translations was obtained by considering the better translation. Next, two English language experts re-translated the final version into English. After this stage, the original English version was compared with the English version obtained by the translation of language experts by the research team, and finally, with the necessary corrections and editing, the final Persian version was approved. To determine the formal validity, the writing style, wording and logical and interesting appearance of the scale are used. For this purpose, the questionnaire was given to 10 older people who met the inclusion criteria and they were asked to express their opinions about the content, clarity, eligibility, simplicity and easy understanding of the instrument terms and the ease of completing the questionnaire. In this section, the level of difficulty (difficulty in understanding phrases and words), the degree of appropriateness (appropriateness and good relationship of phrases with the dimensions of the questionnaire) and ambiguity (the possibility of misunderstandings of phrases or the existence of inadequacies in the meanings of words) were examined. Also, the opinions of experts in the content validity stage were used to improve the formal validity of the scale. For this purpose, 5 related experts were asked to provide the necessary feedback after a qualitative review of the questionnaire based on the criteria of grammar, use of appropriate words, necessity, importance, placement of phrases in their proper place and proper scoring.
In order to determine the validity of the construct in this study, the Known Group Comparison was used, which is used to determine the extent to which the questionnaire can separate different subgroups. In other words, this type of validity determines the capability and ability of a scale in differentiating respondents according to the set criteria and assumptions. In this study, the parameter used was disease control. For this purpose, the scale score was compared between two groups of patients with and without blood pressure control using independent t-test. We expected people with controlled disease to score higher on the questionnaire than patients without controlled blood pressure. In order to evaluate the validity of the criterion, Pearson correlation coefficient was measured as the score of two questionnaires of H-SCALE and MMAS-8.
Confirmatory factor analysis method was used to determine the validity of the structure. In this section, convergent validity and divergent validity of the questionnaire were examined by Smart PLS software. Factor loads, mean extraction variance (AVE) and combined reliability are used to measure convergence validity. For convergent validity, all factor loads must be above 0.6 and significant. The mean of extracted variance is greater than 0.5 and the combined reliability is greater than the mean of extracted variance. Divergent validity is measured by cross loading, Fornell-Larcker test and Heterotrait-Monotrait Ratio. In the cross loading, the factor load of each question on its own construct must be greater than the factor load of that question on other constructs, ie the factor load of each question on its variable must be at least 0.1 greater than the factor load of the same question on other variables. In Fornell Larcker test, the root mean square of the extracted variance of each variable must be greater than the maximum correlation of that variable with other variables. The Heterotrait-Monotrait Ratio (HTMT) is also a reliable and new method for assessing divergent validity. If the values of HTMT index are below 0.9, the construct validity of the questionnaire is confirmed (19).
Internal consistency, composite reliability, and communalities are the main criteria used to assess the reliability of the questionnaire. Cronbach's alpha above 0.6, the composite reliability above 0.7 and the communalities index above 0.5 are confirmed (20).
The mean age of participants was 58.34(+ 10.3) years. The majority of participants were females (68%) and their education level 40% were illiterate or elementary. Also, 84% of the participants were married and 75.5% of them owned housing. The mean duration of the disease was 8.85(+ 6.42).
In order to evaluate the known group comparison by the Persian version of the questionnaire based on disease control, independent t-test was used (Table 1).
| Variable or H-SCALE subscale | Controlled hyprtension (Standard deviation) average n = 157 | Uncontrolled hyprtension (Standard deviation) average n = 37 | P-value |
|---|---|---|---|
| Medicationa | 20.16 (2.51) | 16.16 (5.30) | 0.003 |
| Healthy eating or Low-salt Diet | 33.32 (11.22) | 31.81 (9.53) | 0.041 |
| Physical Activity | 3.96 (4.45) | 3.86 (3.81) | 0.431 |
| Tobacco exposure | 1.15 (1.92) | 2.08 (2.36) | 0.152 |
| Weight management | 23.65 (8.92) | 22.18 (9.66) | 0.501 |
a : are taking medication.
The test results showed that the mean score of the questionnaire in the construct of adherence to drug use and nutrition was higher in patients who had controlled blood pressure than patients who did not control blood pressure (P = 0.003).
The correlation coefficient between the scores obtained from the H-SCALE and MMAS-8 is shown in Table 2.
| H-SCALE subscale | medication | Healthy eating | Physical activity | Tobacco exposure | Weight management | Adherence to treatment |
|---|---|---|---|---|---|---|
| medication | 1 | |||||
| Healthy eating | 0.118 | 1 | ||||
| Physical activity | -0.076 | 0.175* | 1 | |||
| Tobacco exposure | -0.098 | -0.069 | -0.092 | 1 | ||
| Weight management | 0.219** | -0.241** | -0.178** | -0.456** | 1 | |
| Adherence to treatment | 0.432** | 0.036 | 0.110* | -0.199** | 0.166* | 1 |
| * Significant at the level of P < 0.05, ** Significant at the level of P < 0.01 | ||||||
There was a significant correlation between the scores obtained from all dimensions of the questionnaire except nutrition by MMAS-8.
The factor loadings of the questionnaire were the effects of the level of self-care activity in all constructs and were higher than 0.5 except for three items (Fig. 1).
Figure 1. Confirmatory Factor Analysis of the Persian version of the Hypertension Self-Care Activity Level Effects (H-SCALE)
Based on the results of Table 3, the mean of extracted variance of the constructs except the healthy eating construct was greater than 0.5 and the composite reliability of all variables was greater than the mean of extracted variance, so most of the questionnaire constructs had convergent validity. Table 3 showed the Cronbach's alpha coefficients, composite reliability and communalities index of all constructs.
| Variable | Average Variance Extracted (AVE) | Composite reliability | Cronbach's alpha | Communalities |
|---|---|---|---|---|
| medication | 0.888 | 0.975 | 0.933 | 0.956 |
| Healthy eating | 0.356 | 0.792 | 0.695 | 0.688 |
| Physical activity | 0.570 | 0.837 | 0.846 | 0.291 |
| Tobacco exposure | 0.729 | 0.842 | 0.652 | 0.824 |
| Weight management | 0.445 | 0.837 | 0.748 | 0.796 |
The results of Tables 4 showed that the mean of extracted variance of all variables was obtained from the correlation of that variable with other larger variables. Therefore, divergence validity at the level of study construct was ensured.
| Variable | 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|---|
| 1. medication | 0.596 | ||||
| 2. Healthy eating | -0.101 | 0.938 | |||
| 3.Physical activity | 0.060 | -0.159 | 0.755 | ||
| 4. Tobacco exposure | 0.024 | -0.100 | 0.132 | 0.854 | |
| 5.Weight management | 0.266 | -0.205 | 0.043 | 0.197 | 0.587 |
Also, the results of Table 5 showed that the HTMT index in all constructs is less than 0.9, so the divergent validity of the questionnaire was confirmed.
| Variable | 1 | 2 | 3 | 4 |
|---|---|---|---|---|
| 1. Healthy eating | ||||
| 2. medication | 0.175 | |||
| 3.Physical activity | 0.140 | 0.117 | ||
| 4. Tobacco exposure | 0.182 | 0.117 | 0.125 | |
| 5.Weight management | 0.383 | 0.240 | 0.200 | 0.256 |
The aim of this study was to assess the psychometric properties of the H-SCALE with an Iranian population. In the present study, the translation of the questionnaire has been done carefully by fluent and knowledgeable people, following the principles of translation and paying attention to its correct process and accuracy in cultural adaptation of meanings. One of the strengths of the study is the observance of the main steps recommended according to reliable sources for the translation process and ensuring the cultural conformity of the scales.
In this study, to evaluate the construct validity, the method of comparison of known groups was used using the blood pressure control parameter. The results of the analysis showed that the scale score of patients with controlled blood pressure was significantly higher than expected. In the original version, Warren-Findlow J et al. also showed a significant relationship between low blood pressure and scale scores (15).
In order to evaluate the criterion validity, Pearson correlation coefficient was measured as the score of two questionnaires of H-SCALE and MMAS-8. There was a significant correlation between the scores obtained from the H-SCALE and Morisky treatment adherence in all dimensions except nutrition.
In the study, the Cronbach's alpha coefficient of the scale showed an acceptable internal consistency of the scale expressions that is consistent with the main study. In a study by Warren-Findlow J et al. in 2013 (16). to evaluate the psychometric properties of the H-scale questionnaire in English, Cronbach's alpha coefficient subscales were medication: 0.77, DASH diet: 0.67 Physical activity: 0.77, Tobacco exposure: 0.78, Weight management: 0.86, Alcohol intake: 0.88 so that the internal consistency of all subscales except DASH diet was desirable. In the study of Warren-Findlow J et al., which was conducted in 2018 with the aim of examining the psychometric properties of the H-SCALE, Cronbach's alpha coefficient was reported as subscales between 0.75 and 0.91, which indicates acceptable to good internal consistency (17).
Non-random sampling restricts the generalizability of the study findings. Consequently, multi-state studies with larger sample sizes are recommended. Moreover, since we evaluated only the validity and the reliability of the H-SCALE, more studies for assessing the responsiveness of the H-SCALE are also recommended.
The results of this study showed that the H-SCALE had good psychometric properties. This scale can be used to measure blood pressure self-care level and healthcare outcomes in different clinical and research settings. The H-SCALE is easy to understand and respond and takes, less than 10 minutes to be completed. It is notable that the H-SCALE is used for both measuring self-care and assessing the effects of interventions on patients’ outcomes.
Hypertension Self-Care Activity Level Effects
systolic blood pressure
disability-adjusted life years
Morisky Medication Adherence Scale
Hypertension self-care profile
International Quality of Life Assessment Project
Heterotrait-Monotrait
Ethics approval and consent to participate:
The research followed the tenets of the declaration of Helsinki, and approval to conduct the study was obtained from the Medical Ethics Committee at Qom University of Medical Sciences (registration number: IR.MUQ.REC.1400.009). The study was explained to the participants who met the eligibility criteria in a simple and comprehensible manner, and they were asked to repeat the information to ensure their understanding. Written informed consent was obtained from the participants before inclusion into the study. An impartial literate witness was present during the entire informed consent process with the illiterate participant. Participants were free to withdraw from the study without any effect on their treatment process.
Availability of data and materials: The datasets used and/or analysed during the current study available from the corresponding author on reasonable request.
Competing interest: The authors declare that they have no competing interests.
Consent for publication: not applicable
Funding: This work was supported by the Qom university of medical science.
Authors’ contributions:
Study Design: ZT
Data Collection: ZT, MS, FS, MJ
Data Analysis : ZT, MS
Written of manuscript: MS, ZT, FS, MJ
Preparing of tables: ZT, MS
Revise and edit of manuscript: MS, ZT, FS, MJ
Acknowledgments:
The study was part of a student research project with a code of ethics IR.MUQ.REC.1400.009 and was supported by the Qom University of Medical Sciences. We are grateful to Dr. Warren-Findlow for permission to use scale and patients and staff of Qom Teaching Hospitals and others who assisted in the research.