運用計劃行為理論探討台灣年輕男性間性行為者之無套肛交意圖相關因素

Abstract

背景：近年之疫情資料顯示，男性間性行為者佔所有新HIV感染比例超過80%，且超過70%新感染發生於15至34歲年齡層，研究指出在男性間性行為者族群內，主要HIV傳播途徑為無套肛交。 目標：運用計劃行為理論 (Theory of Planned Behavior, TPB) 探討台灣年輕男性間性行為者之無套肛交意圖相關因素。 方法：本研究透過網路匿名自填式問卷從694位男性間性行為者收集以下資料：背景特徵、TPB構念相關資訊、無套肛交意圖。運用多變量邏輯斯迴歸納入TPB直接測量與TPB間接測量構念進行依性角色分層分析無套肛交意圖相關因素。 結果：運用中位數為切點，378 (54.5%) 男性間性行為者擁有低無套肛交意圖，316 (45.5%) 擁有高無套肛交意圖。運用TPB直接測量構念，行為態度和無套肛交意圖有顯著關係，擁有正像行為態度者相對負向行為態度者擁有高無套肛交意圖的AOR高達29.64–38.63倍，擁有高度支持的主關規範之不分0/1 (AOR=4.23) 與1號 (AOR=5.15) MSM有比較高的無套肛交意圖，間接測量構念：正向結果評價與阻礙因子之自覺控制和無套肛交意圖有顯著關係，此外無套肛交相關因素會因不同性角色而改變，即其為一調節因子。 結論：本研究為少數運用計劃行為理論探討年輕男性間性行為者之無套肛交意圖相關因素，發現行為態度為重要直接測量TPB構念，重要間接測量因子包括正向結果評價與阻礙因素之自覺控制，此外無套肛交相關因素會因不同性角色而改變。最後，因TPB構念是可變更的，因此研究發現可提供未來適性之衛教或介入策略所需之實證參考依據。

Background: In recent years, men who have sex with men (MSM) have accounted for over 80% of all new HIV cases in Taiwan, and over 70% of all new HIV cases occurred in those aged 15 to 34 years. Condomless anal intercourse (CAI) has been identified as the main route of HIV transmission among MSM. Objectives: This study used the Theory of Planned Behavior (TPB) to examine factors associated with CAI intention among young MSM in Taiwan. Methods: Through an anonymous online survey, data from 694 MSM were collected on background characteristics, TPB constructs, and CAI intention. Stratified multivariate logistic regression by sexual role, using direct and indirect measures of TPB constructs, was performed to examine factors associated with CAI intention. Results: Using the median as a cutoff, 378 (54.5%) and 316 (45.5%) MSM were classified as having low and high CAI intention, respectively. When direct TPB measures were applied, MSM with relatively positive attitude toward the behavior (ATB) were significantly more likely to have high CAI intention (AOR=29.64–38.63 depending on sexual role). Versatile and insertive MSM with relatively supportive SN were 4.23 and 5.15 times more likely to have high CAI intention, respectively. When indirect TPB measures were applied, the indirect factors that were consistently associated with CAI intention for all three sexual roles were attitudinal evaluations of positive behavioral outcomes and ease of behavior under constraining conditions. The association between TPB constructs and CAI intention varied depending on sexual role. Conclusions: This study was among the first in Taiwan that used TPB to examine CAI intention among young MSM. ATB is perhaps the most important direct measure TPB construct associated with CAI intention. The indirect TPB measures that were consistently associated with CAI intention were attitudinal evaluations of positive behavioral outcomes and ease of behavior under constraining conditions. Also, the significance and strength of the association between TPB constructs and CAI intention varied, depending on sexual role. Finally, since the TPB constructs examined in this study are modifiable, the findings can inform future HIV/AIDS prevention efforts tailored according to sexual role to optimize the effectiveness of the programs.