高血壓病患疾病知覺與治療遵從行為關係之探討：結構方程模式之驗證

高血壓病患疾病知覺與治療遵從行為關係之探討：結構方程模式之驗證

 過去數十年，高血壓治療的成效雖然大幅提昇，但高血壓疾病控制的成效卻十分有限。病人對治療處置不遵從為影響疾病控制成效的重要

因素之一。雖然，探討不遵從的研究很多，但較少研究探討影響病人行為的動機。依據自我調整理論的假設，疾病認同、病因解釋和疾病 表徵是影響病人治療遵從行為的重要變項。然而，高血壓被認為是沒有症狀的隱形殺手，高血壓病人如何接受疾病進而遵從治療，很少研 究探討。基於此研究旨趣，本研究以自我調整理論假設為架構，以結構方程模式分析技巧，檢視可預測高血壓病人治療遵從的因果行為模 式，特別是疾病認同的角色。

 本研究採橫斷式問卷調查法，以中部某縣市三家教學醫院心臟內科門診就診的高血壓病人為對象，依取樣和排除條件立意取樣 355 位病，

以結構式問卷：疾病知覺量表（含疾病認同、病因解釋和疾病表徵）、治療遵從行為量表（含藥物治療和自我照顧）收集資料。資料分析 使用 SPSS 11.0 PC+ 軟體進行描述性和推論性統計之分析，以 LISREL 8.54 版檢視量表的測量模式和理論資料模式關係的適配度。研究結果 發現： (1) 在疾病知覺和遵從行為的相關分析上，相關係數最強的分別為治療控制與和藥物治療遵從總分（ r=0.23 ），和個人控制與自我照 顧遵從總分（ r=0.33 ）；而且，病因解釋越多，藥物治療和自我照顧遵從行為越低； (2) 在分別比較診斷前後，是否有高血壓症狀的組別，

與治療遵從行為的關係時發現，診斷前沒有高血壓症狀者，在運動和自我照顧總分上，顯著高於不確定是否有症狀者。診斷後沒有和有高 血壓症狀者，分別在藥物自我調整得分和自我照顧總分得分上，顯著高於不確定診斷後是否有症狀者。而且，診斷後沒有症狀者，在不健 康飲食和運動得分上，亦顯著高於不確定診斷後是否有高血壓症狀者； (3) 驗證性因素分析結果顯示，疾病認同、病因解釋和疾病表徵，和 遵從行為量表（含藥物和自我照顧）皆有良好的因素建構效度、收歛效度、區辨效度、組成信度和內在一致性； (4) 結構方程模式結果顯示

，資料與理論模式的適配度佳。在控制個案收縮壓、年齡、降壓藥顆數和合併症等變項的影響後發現，疾病認同可經由病因解釋（ t=4.05

， γ=0.38 ）和控制（ t=-2.28 ， γ=-0.24 ），分別影響高血壓病人藥物治療遵從行為和自我照顧遵從行為；控制對藥物治療遵從和自我照顧 遵從行為的直接效應分別為 β=0.35 （ t=3.66 ）和 β=0.42 （ t=2.17 ）。病因解釋對藥物治療遵從行為影響的直接效應為 β=-0.17 （ t=-2.31 ）。

雖然，疾病認同和病因解釋對負向表徵有直接效應，但負向表徵對治療遵從行為沒有影響。最後模式的路徑效應共可解釋藥物治療遵從行 為 22.2% 的變異量，和 44.9% 自我照顧遵從行為的變異量。上述結果顯示高血壓病人的俗民見解在其治療遵從行為中的重要性，研究結果 也支持以自我調整理論做為探討高血壓病人治療遵從行為研究架構的適用性。

 依據本研究結果建議，要提升高血壓病人對治療遵從行為時，應增加病人對疾病的控制能力和澄清不適當的病因解釋，而非單純強調疾病

對個人健康負面的影響。再者，高血壓病人對疾病有自己的看法，特別是症狀經驗，即便此經驗可能是主觀的，仍會間接影響病人治療遵 從行為。過度強調高血壓的無症狀性，可能加重病人疾病知覺的衝突，徒增持續接受治療的障礙，因為症狀經驗越多，病人對病因的解釋 越多，對疾病控制能力越低，藥物治療和自我照顧遵從行為越低。對於有症狀經驗的高血壓病人，特別是收縮壓比較高，較年輕的病人，

護理人員需了解病人的經驗感受和對疾病病因解釋的看法，適時予以衛教澄清，以減少接受治療的阻力，提升治療遵從度。

The relationships between illness perceptions and adherence to therapeutic regimens among patients with hypertension: A structural

modeling approach

 Although the therapeutic effectiveness of hypertension has been significantly advanced in the past decades, the control rate for hypertension is still lim ited. Non-adherence to therapeutic regimens is considered to be responsible for the low control rate. Although many studies have been conducted to ex plore the issues of non-adherence, few are focused on patients’ motives. For the study interest, the Self Regulation Model (SRM) is selected as the fra mework to examine the theoretical assumption of causal model for adherence to therapeutic regimens of patients with hypertension in Taiwan. Accord ing to the assumption of the SRM, identity and cause are significant motives for patients seeking medical helps. But, very few studies include illness id entity in the adherence study for hypertension is asymptomatic. The specific aim of the study is to explore simultaneously the roles of identity, causal a ttribution and illness representations on patient adherence behavior using the technique of structural equation modeling.

 The study is descriptive with a questionnaire survey design. A purposive sampling will be used to draw out the sample from 3 teaching hospitals in cen tral Taiwan according to the selection and exclusion criteria. A total of 355 valid cases were included in the study. Structured questionnaires such as Ill ness Perception Questionnaire-Revised (including identity, cause and illness representations) and the Adherence Inventory including the Medication A dherence Inventory (MAI) and the Inventory of Adherence to Self Management (IASM) were used for data collection. Data were analyzed by descript ive statistics as well as inferential statistics using the software of SPSS 11.0 PC+. The software of LISREL version 8.54 was used to analyze the measu rement model and structural equations model of adherence to therapeutic regimen of patients with hypertension.

 The results of the study found: (1) the strongest correlations were found between treatment control and the total score of MAI, personal control and the total score of IASM. The higher scores of the causes were associated with the lower adherent rates on both the MAI and IASM; (2) The results of AN OVA showed that those who were unsure if they had experienced symptoms after a hypertension diagnosis were more likely to self-regulate (increase or decrease) prescribed medications and less adherent to self management than those without or with symptoms. Those who were no symptoms before or after diagnosis were more likely to adhere to self management activities than those who were uncertain; (3) the findings of confirmatory factor anal ysis provided evidences supporting both the Chinese versions of Illness Perception Questionnaire – Revised, and Adherence Inventories to be reliable and valid instruments in assessing patients’ beliefs about illness and adherence behavior; (4) the results of structural equation model showed that after controlling the effects of systolic blood pressure, age, total number of the antihypertensive, and comorbidity, identity may influence both patients’ adh erence to medication and self management indirectly through control and cause. Negative illness representations showed no effect on both adherence t o medication and self management recommendations. Together, direct and indirect effects of control and cause explained 22.2% of variance in adhere nce to medication; while the explained variance of adherence to self management recommendations were 44.9%.

 The findings imply that improvement of sense of controllability can contribute to enhance patients’ adherence to therapeutic regimens, but not negativ e illness representations. Patients have their own views of disease, especially for those who experienced symptoms related to hypertension. Even thoug h symptom is subjective, it indirectly influences patients’ adherence to therapeutic regimens. The more symptoms the patient report, the more attributi ons of the illness, the poor sense of controllability of the illness, the lower adherence rate to therapeutic regimens. For patients with high blood pressur e related symptoms, the health professionals need to assess individual beliefs about the symptom and illness attribution, clarify misconceptions, so that the barriers of adherence may be reduced, and the adherence rate may be improved. In sum, the findings support the utility of SRM as a theoretical fra mework in understanding patient behavior of adherence to therapeutic regimens.