Minimal clinically important difference (MCID) for the functional assessment of cancer therapy: Cognitive function (FACT-Cog) in breast cancer patients

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• 作者：Yin Ting Cheung^a ; ^b ; Yu Lee Foo^a ; Maung Shwe^a ; Yee Pin Tan^c ; Gilbert Fan^c ; Wei Sean Yong^d ; Preetha Madhukumar^d ; Wei Seong Ooi^e ; Wen Yee Chay^e ; Rebecca A. Dent^e ; ^f ; Soo Fan Ang^e ; Soo Kien Lo^e ; Yoon Sim Yap^e ; Raymond Ng^e ; ^f ; Alexandre Chan^a ; ^b ; ^{phaac@nus.edu.sg" class="auth_mail}
• 关键词：Chemotherapy ; Cognitive function ; Minimal clinically important difference ; FACT-Cog ; Quality of life ; Breast cancer
• 刊名：Journal of Clinical Epidemiology
• 出版年：July 2014
• 年：2014
• 卷：67
• 期：7
• 页码：811-820
• 全文大小：321 K

文摘

This is the first reported study to determine the minimal clinically important difference (MCID) of Functional Assessment of Cancer Therapy–Cognitive Function (FACT-Cog), a validated subjective neuropsychological instrument designed to evaluate cancer patients' perceived cognitive deterioration.

Study Design and Setting

Breast cancer patients (n = 220) completed FACT-Cog and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC-QLQ-C30) at baseline and at least 3 months later. Anchor-based approach used the validated EORTC-QLQ-C30–Cognitive Functioning scale (EORTC-CF) as the anchor for patients who showed minimal deterioration and a receiver operating characteristic (ROC) curve to identify the optimal MCID cutoff for deterioration. Distribution-based approach used one-third standard deviation (SD), half SD, and one standard error of measurement (SEM) of the total FACT-Cog score (148 points).

Results

There was a moderate correlation between changes in FACT-Cog and EORTC-CF scores (r = 0.43; P < 0.001). The EORTC-CF–anchored MCID was 9.6 points (95% confidence interval: 4.4, 14.8). The MCID from the ROC method was 7.5 points (area under the curve: 0.75; sensitivity: 75.6%; specificity: 68.8%). For the distribution-based approach, the MCIDs corresponding to one-third SD, half SD, and one SEM were 6.9, 10.3, and 10.6 points, respectively. Combining the approaches, the MCID identified for FACT-Cog ranged from 6.9 to 10.6 points (4.7–7.2% of the total score).

Conclusion

The estimates of 6.9–10.6 points as MCID can facilitate the interpretation of patient-reported cognitive deterioration and sample size estimates in future studies.