糖尿病健康促進機構醫師對血糖控制不佳之第2型糖尿病人選擇抗糖尿病藥物之行為意向及其相關因素之探討

Abstract

本研究之主要目的在於運用Ajzen 所提出的計劃行為理論（Theory of Planned Behavior）來探討糖尿病健康促進機構醫師在未來半年內，針對經衛教指導、積極飲食與運動控制及服用兩種口服抗糖尿病藥物達最大劑量，且A1C仍≧7.5%的第2型糖尿病人，其選擇抗糖尿病藥物之行為意向。研究對象為任職於136家糖尿病健康促進機構且診治門診糖尿病人的醫師。研究工具的設計乃根據開放式問卷的填答及電話訪問的結果，篩選出顯著信念而編制成結構式問卷，再運用郵寄問卷的方式進行資料收集，共計回收有效問卷214份，分佈於92家機構，回收率為43.8%。 本研究分別測量研究對象對選擇胰島素及口服抗糖尿病藥物在態度、主觀規範、自覺行為控制及行為意向的得分，再經過兩者得分相減，得到差別的分數，以瞭解研究對象在各變項的偏好，有別於該理論一般只針對一種行為選擇的作法，結果指出：（1）差別態度、差別主觀規範、差別自覺行為控制三個變項可以解釋研究對象選擇抗糖尿病藥物之差別行為意向整體變異量的24%，其中以差別態度對差別行為意向的影響力最大，其次分別為差別主觀規範及差別自覺行為控制；（2）在差別態度方面，45.8%的研究對象對這類病人開立胰島素抱持較正向的態度，其中較多數的研究對象認為開立胰島素較口服抗糖尿病藥物，來得適當及效果好。亦有37.4%的研究對象對這類病人開立口服抗糖尿病藥物抱持較正向的態度，其中較多數的研究對象認為開立口服藥較胰島素，來得不麻煩及安全；（3）在差別主觀規範方面，42.1%的研究對象覺得大多數的重要參考對象認為他較應該開立胰島素，僅有12.6%的研究對象覺得大多數的重要參考對象認為他較應該開立口服抗糖尿病藥物，而另有45.3%的研究對象覺得大多數的重要參考對象對他開立此兩種藥物的贊成程度是相同的；（4）在差別自覺行為控制方面，75.7%的研究對象認為開立口服抗糖尿病藥物的自主程度高於開立胰島素，其中較多數的研究對象認為對開立口服藥而言，較有把握、自身對治療意見的影響力較大、阻礙因素較少及較容易克服阻礙；（5）研究對象對於選擇抗糖尿病藥物之處方行為的差別態度、差別主觀規範與其構成要素之交乘積和間呈現正相關，差別自覺行為控制則與其構成信念亦呈現正相關，皆符合計劃行為理論的假設；（6）為進一步瞭解處方行為意向不同者在各信念間的差異，依照研究對象選擇抗糖尿病藥物之差別行為意向，剔除中立意見者73位，區分為胰島素及第三種口服抗糖尿病藥物取向組，兩組比較發現：1.差別行為信念方面：胰島素取向組較第三種口服抗糖尿病藥物取向組更認同胰島素較口服藥能有效控制血糖、降低罹患糖尿病併發症的風險、延緩β細胞功能惡化、降低口服藥物交互作用、改善胰島素阻抗性、彈性調整藥物劑量及改善病人的生活品質。2.差別規範信念方面：雖然兩組皆覺得醫院、新陳代謝科醫師、糖尿病相關學會、糖尿病衛教人員及實證研究等重要參考對象比較支持研究對象開立胰島素，但以胰島素取向組感受到的贊成程度較為強烈。兩組皆覺得病人較支持研究對象開立口服抗糖尿病藥物，但以第三種口服抗糖尿病藥物取向組感受到的贊成程度較為強烈。3.差別控制信念方面：胰島素取向組較同意這類病人出現糖尿病併發症比較會促使其改用或增加胰島素而非口服藥；（7）研究對象之社會人口學變項與其選擇抗糖尿病藥物的差別行為意向沒有顯著相關性；（8）本研究對象在未來半年內，對這類病人開立抗糖尿病藥物的選擇意向，傾向開立胰島素者佔57.0 %，傾向開立第三種口服抗糖尿病藥物者則佔32.7 % 基於以上研究結果，歸納出結論：計劃行為理論之主要變項--態度、主觀規範及自覺行為控制，能預測研究對象之處方抗糖尿病藥物之行為意向。其中以態度及主觀規範，較具影響力；處方行為意向不同組在態度、主觀規範及自覺行為控制之構成信念方面亦有顯著差異。最後，根據研究結果，提供建議供醫療及教育相關機構參考。

The purpose of this study was to explore the physicians’ intentions to choose antidiabetic agents in the next six months by applying the Ajzen’s theory of planned behavior. A clinical vignette was designed to elicit physicians’ opinions: for type 2 diabetic patients who have had hygiene education and guidance, active diet and exercise control, and taking the maximum dosage for two oral antidiabetic agents, whose A1C is still ≧7.5%, to determine the intention for choosing antidiabetic agents. The sample population was selected from the physicians who take care of ambulatory diabetic patients in the 136 Institutions of Diabetes Health Promotion. The design of research instrument was based on the results of an open-ended questionnaire and telephone interviews from the sample population, and then to elicit salient beliefs. According to salient beliefs, the structured questionnaire was developed, and then structured questionnaires were mailed to collect data. The total number of valid questionnaires was 214, distributed to 92 institutions, and the overall valid response rate was 43.8%. In the study, attitude, subjective norm, perceived behavioral control, and behavioral intention were measured to get scores about choosing insulin and OAD by respondents respectively. Then, two scores were subtracted, creating a differential score which presented the views of respondents. This method was different from the traditional method of the theory, which was generally applied to explain one-choice behavior. The results show: (1) All three of the constructs in the theory—differential attitude, differential subjective norm, and differential perceived behavioral control could effectively explain 24% of variance of the differential intention to prescribe antidiabetic agents . Of which, differential attitude have the greatest influence for differential intention, followed by differential subjective norm and differential perceived behavioral control;（2）Regarding differential attitude, 45.8% of respondents had a more positive attitude toward prescribing insulin than OAD, because most of them believed prescribing insulin was more appropriate and effective. But 37.4% of respondents also had a more positive attitude toward prescribing OAD than insulin, most of them believed prescribing OAD was less inconvenient and more safer; (3)Regarding differential subjective norm, 42.1% of respondents felt most of the important referents expected he/she should prescribe insulin. Only 12.6% of respondents felt most of the important referents expected he/she should prescribe OAD. Besides, 45.3% of respondents felt most of the important referents agreed no matter what kind of drugs was prescribed by them; (4)Regarding differential perceived behavioral control, 75.7% of respondents believed the autonomy of prescribing OAD was higher than that for insulin, of which more respondents believed that in prescribing OAD, they were more confident, had more influence over treatment opinion, fewer obstacles, and such obstacles was easier to overcome; (5)The differential attitude of respondents toward prescribing intention was positively related to the sum of the product of differential behavioral beliefs multiplied by outcome evaluations（Σ（b1-b2）ii•ei). The differential subjective norm of respondents toward prescribing intention was positively related to the sum of the product of differential normative beliefs multiplied by motivations to comply(Σ（nb1-nb2）i•mc). The differential perceived behavioral control of respondents toward prescribing intention was also positively related to the sum of the product of differential control beliefs (Σ（cb1-cb2）i). These results were also consistent with the theory of planned behavior; (6)According to differential behavioral intention, excluding the 73 neutrals, respondents were divided into insulin-oriented and OAD-oriented group. There were significant differences in differential beliefs between these tow groups. For instance: 1.Regarding differential behavioral beliefs, the insulin-oriented group was more likely to agree insulin was more effective, could decrease the risk of diabetes-related complications, delay the failure of βcell function, decrease the interaction of oral agents, improve insulin resistance, adjust the dosage flexibly, and improve patients’ quality of life. 2.Regarding differential normative beliefs, though both groups felt important referents, ex: hospitals, metabolism specialists, diabetes-related institutions, diabetes educators, and evidenced-based research, support them to prescribe insulin, the insulin-oriented group felt stronger support than the OAD-oriented group. Both groups felt patients support them to prescribe OAD, but the OAD-oriented group felt stronger support than insulin-oriented group. 3.Regarding differential control beliefs, the insulin-oriented group was more likely to agree the occurred-complications would get them to prescribe insulin; (7)The social demographic variables were not correlated with the differential intention to prescribe antidiabetic agents; In addition, (8) In choice intention, 57.0% of respondents intended to choose insulin, and 32.7% intended to choose the 3rd OAD in the next six months. According to above results, the conclusion was made: all three of the constructs in the theory — attitude, subjective norm, perceived behavioral control, made significant contributions to predict respondents’ intentions to prescribe antidiabetic agents. Among them, attitude and subjective norm were the main effective variables; For the group with different intentions in prescriptions, there were also significant differences in belief composites that are assumed to determine attitude, subjective norm, and perceived behavioral control. In addition, based on the results, the researcher proposed suggestions to health care and educational institutions.