2007Mar201 Journal Club for Analysis of Complex Datasets Cui Y, Shu X-O, Gao Y-T, Cai H, Tao M-H, Zheng W. Assocation of ginseng use with survival and quality of life among breast cancer patients. Am J Epidemiol 2006; 163:

2007Mar202 Summary Objective: evaluate effects of ginseng use on breast cancer survival & survivors’ QOL. Design: cohort study. Setting: Shanghai Breast Cancer Study. –Population-based case-control study. Subjects: women aged years w/ newly diagnoses breast cancer Aug1996 – Mar1998 (N=1455). –Cases from Shanghai Study. –Followed through Dec2002.

2007Mar203 Summary (2) In-person interviews conducted ~66 days post-dx. Exposure: ginseng use. –Type, duration, & frequency of use. Outcome: –Overall survival. –Disease-free survival. –QOL. Assessed during in-person follow-up interviews for 1065 of 1248 surviving patients. Sociodemographic, medical, & other CAM info collected as well.

2007Mar204 Analysis Overall survival & disease-free survival: –Kaplan-Meier plots & log-rank tests. –Proportional hazards regression. Adjusted for age, education, income, stage of disease, estrogen & progesterone receptor status, & std cancer tx’s. QOL: –Linear regression. Adjusted for age, marital status, education, income, menopausal status, recurrence of disase, time since cancer dx, & use of other CAM.

2007Mar205 Results: survival Ginseng use: –398 (27.4%) regular use. –1057 (72.6%) nonusers (never used before cancer dx). –All ginseng users received 1+ mainstream tx.

2007Mar206

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9 Results: QOL Ginseng use: –Before/after dx: Never use before or after. Use before but not after. Use after but not before. Use both before & after. –Ever/current use after dx. –Cumulative use by current users.

2007Mar2010

2007Mar2011 Strengths Large population-based sample. Excellent participation rate. All ginseng users received mainstream tx: –provides well-defined sample to evaluate ginseng as complementary rather than alternative therapy. Differentiate between types of ginseng & use: –Red (hot) used for short periods. –White Asian & American (cold) used for longer periods.

2007Mar2012 Strengths (2) QOL: –Assessed timing of ginseng use (before/after dx). –Assessed ever/current use: Ever users quit using ginseng? Placebo/healthy user effect for current users? –Assessed dose-response. “…caution is required in interpreting the results…findings need to be confirmed in more rigorous and randomized clinical trials.”

2007Mar2013 Limitations Lack of info on ginseng use after dx for patients who died before follow-up interview. Unable to exclude confounding by other CAM. Self-reported data: potential recall & self- report bias. Could not evalute methods of ginseng use.

2007Mar2014 Suggestions: Survival Adjusted survival curves. Time-dependent ginseng use (eg, QOL analysis). Account for timing of cancer tx. Adjustment for other “healthy patient” factors possibly associated with ginseng?

2007Mar2015 Suggestions: QOL “…lack of ginseng’s effect on physical well- being obsrved in this study may be due to the fact that patients had already fully recovered physically by the time the survey was conducted.” –Time-dependent analysis of ginseng use & physical state. –Authors state need to further study effect of ginseng on physical well-being at earlier time points.

2007Mar2016 Sensitivity analysis Lin DY, Psaty BM, Kronmal RA. Assessing the sensitivity of regression results to unmeasured confounders in observational studies. Biometrics 1998; 54: Assess effect of unmeasured binary or normal confounder. –For binary confounder, effect is function of prevalence & effect among E+/E- groups.

2007Mar2017 Example from Lin et al. (1998)