Sensitivity of Self-reported Opium Use in Cancer Pa- tients: Implications for conducting epidemiological studies

Background: Underreporting bias related to opium use is a significant methodological issue that can threaten the results of epidemiologic studies, particularly when opium use is the exposure of interest. In our current study, we aimed to measure the sensitivity of opium use. among cancer patients and identify the contributing factors Method: In a cross-sectional study, we examined the sensitivity of self-reported opium use among cancer cases. In this study, we avoided using urine tests as the gold standard to prevent false positive results, given that most cancer patients use opioids to alleviate their pain. Instead, we relied on their reports of use to anesthesiologists as the gold standard and compared it with their reports to interviewers to calculate sensitivity Results: The sensitivity of self-reported opium use among cancer patients was approx- imately 63.33% (95% CI: 43.86% – 80.07%). Interestingly, this sensitivity was signifi- cantly higher among cigarette users 88.24% (95% CI: 63.56% – 98.54%) compared to non-users 30.77% (95% CI: 9.09% – 61.43%). Additionally, the sensitivity of self-reported opium use was higher among alcohol users and participants with low socioeconomic status compared to their counterparts, although these differences were not statistically significant. Conclusion: The observed sensitivity of self-reported opium use among cancer pa- tients underscores the importance of meticulous and comprehensive approaches for collecting and interpreting self-reported substance use data. Researchers and policy- makers should consider contributing factors to the sensitivity of self-reported opium use.