| Objective:The medication literacy scale for patients with hypertension with 37items has moderate construct validity,and the clinical applicability and popularization were relatively insufficient,so it needs to be further revised.This study aimed to revise the medication literacy scale for patients with hypertension and to test its reality and validity,and then apply it to explore the associations between medication literacy and blood pressure control.Methods:(1)After obtaining the original author’s authorization to carry out the revision of the scale,focus group discussions were used to revise the content and items of the original medication literacy scale for patients with hypertension based on the established evaluation index system of medication literacy for hypertensive patients.After unifying the revision opinions,the initial revised scale was formed.Then,we invited experts who were proficient in clinical medicine,nursing,pharmacy or,public health to conduct two-round expert consultation for the further revision of the scale.After that,15 patients with hypertension with quota sampling method were invited to participate in interviews to assess the item clarity of the revised scale,and then the revised medication literacy scale for patients with hypertension for the pilot survey was developed.In the stage of pilot survey,a total of 110 eligible patients with hypertension were selected to participate in the pilot survey for item selection with four methods,i.e.,Cronbach’s coefficientα,item discrimination analysis,correlation coefficient method and exploratory factor analysis.Finally,the revised medication literacy scale for patients with hypertension for formal survey was developed.A total of 339 eligible hypertensive patients were selected to carry out a formal survey to test the reliability and validity of the scale.The reliability was evaluated with Cronbach’sαcoefficient,split-half reliability and test-retest reliability.The validity was evaluated with content validity,construct validity,convergent validity,discriminant validity and criterion-related validity.(2)A total of 378 eligible hypertensive patients participated in a cross-sectional survey with the revised scale to test the status of medication literacy.The relationship between medication literacy with blood pressure control among hypertensive patients was identified with a chi-square test,two independent sample t-test and logistic regression analysis.Results:(1)An initial revised medication literacy scale for patients with hypertension with 26 items was developed after focus group discussions.Then,a revised medication literacy scale for patients with hypertension with 22 items was developed after the two-round expert consultation.Based on item analysis,the revised medication literacy scale for patients with hypertension was identified.The revised scale contained 18 items and four dimensions,i.e.,medication knowledge dimension with 4 items,medication attitude dimension with 3 items,medication skill dimension with 7 items and medication practice dimension with 4 items.The results showed that the Cronbach’sαcoefficient of the revised scale was 0.802,and each dimension ranged from 0.639 to 0.815.The split-half reliability coefficient of the revised scale was 0.709,and each dimension ranged from0.648 to 0.792.The test-retest reliability coefficient of the revised scale was 0.851,and each dimension ranged from 0.655 to 0.857.The S-CVI/UA of the revised scale was 0.889,the S-CVI/Ave was 0.981,the S-CVI/UA of each dimension ranged from 0.958 to 1.000,and the I-CVI of each item ranged from 0.833 to 1.000.Confirmatory factor analysis results showed that the model fit well(X~2/df=1.727,RMSEA=0.046,GFI=0.932,AGFI=0.909,CFI=0.942,IFI=0.943,TLI=0.930,PCFI=0.782,PNFI=0.725).The SFL for most items was greater than 0.50,the CR of four dimensions was greater than 0.60,and the AVE was greater than 0.30,which indicated that the convergent validity of the revised scale was acceptable.The√(1of each dimension was greater than the corresponding correlation coefficient,which indicated that the revised scale had good discriminant validity.A total of 178 eligible hypertensive patients were selected to verify the criterion validity.The results showed that the criterion coefficient for the total score of the revised scale and the original scale was 0.797,and the criterion coefficients of each dimension ranged from 0.609 to 0.755.Meanwhile,the correlation coefficients of medication literacy and medication compliance measured by the revised and original scales were 0.330 and 0.298(P<0.001),respectively,which explained 10.6%and 8.9%of the variation in medication compliance,respectively,with a small difference between the results,indicating good criterion-related validity.(2)Among 378 hypertensive patients,the medication literacy score ranged from 10 to 48,with an average score of(28.44±8.78),the blood pressure of 146 patients(38.62%)was controlled,while the blood pressure of 232 patients(61.38%)was uncontrolled.Medication literacy was an influencing factor of blood pressure control rate for hypertensive patients,and the medication literacy score increased by 1 point,and the possibility of blood pressure control for hypertensive patients increased by 1.043times.Conclusion:(1)This study revised the medication literacy scale for patients with hypertension.Compared with the original scale,the revised scale was reduced from 37 items to 18 items,the reliability decreased within the acceptable range,and the construct validity was improved.The convergent validity was acceptable,the discriminant validity and criterion-related validity were good.Thus,the revised scale was conducive to assess medication literacy levels for hypertensive patients scientifically and conveniently.(2)The results showed that the status of medication literacy for hypertensive patients was not optimistic,the level of medication knowledge was the worst,followed by medication skill,medication practice,and the level of medication attitude was relatively best.The blood pressure control rate for the investigated hypertensive patients was 38.62%,which needed to be further improved.We also found that medication literacy was one promoting factor of blood pressure control for hypertensive patients,which indicated that improving the level of medication literacy was of great value in promoting the status of blood pressure control among hypertensive patients. |
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