Comparative Effectiveness of Prostate Cancer Treatments: Evaluating Statistical Adjustments for Confounding in Observational Data

被引:115
作者
Hadley, Jack [1 ,2 ]
Yabroff, K. Robin [3 ]
Barrett, Michael J. [4 ]
Penson, David F. [5 ]
Saigal, Christopher S. [6 ]
Potosky, Arnold L. [7 ]
机构
[1] George Mason Univ, Coll Hlth & Human Serv, Off Dean, Fairfax, VA 22030 USA
[2] George Mason Univ, Coll Hlth & Human Serv, Dept Hlth Adm & Policy, Fairfax, VA 22030 USA
[3] NCI, Div Canc Control & Populat Sci, Bethesda, MD 20892 USA
[4] Informat Management Serv Inc, Rockville, MD USA
[5] Vanderbilt Univ, Dept Urol Surg, Ctr Surg Qual & Outcomes Res, Nashville, TN USA
[6] Univ Calif Los Angeles, David Geffen Sch Med, Dept Urol, Los Angeles, CA 90095 USA
[7] Georgetown Univ, Dept Oncol, Lombardi Canc Ctr, Washington, DC USA
来源
JNCI-JOURNAL OF THE NATIONAL CANCER INSTITUTE | 2010年 / 102卷 / 23期
关键词
ANDROGEN DEPRIVATION THERAPY; INSTRUMENTAL VARIABLE METHODS; HEALTH INTERVIEW SURVEY; PROPENSITY SCORE; RADICAL PROSTATECTOMY; BREAST-CANCER; MEDICARE CLAIMS; SELF-SELECTION; LUNG-CANCER; MEN;
D O I
10.1093/jnci/djq393
中图分类号
R73 [肿瘤学];
学科分类号
100214 ;
摘要
Background Using observational data to assess the relative effectiveness of alternative cancer treatments is limited by patient selection into treatment, which often biases interpretation of outcomes. We evaluated methods for addressing confounding in treatment and survival of patients with early-stage prostate cancer in observational data and compared findings with those from a benchmark randomized clinical trial. Methods We selected 14 302 early-stage prostate cancer patients who were aged 66-74 years and had been treated with radical prostatectomy or conservative management from linked Surveillance, Epidemiology, and End Results-Medicare data from January 1, 1995, through December 31, 2003. Eligibility criteria were similar to those from a clinical trial used to benchmark our analyses. Survival was measured through December 31, 2007, by use of Cox proportional hazards models. We compared results from the benchmark trial with results from models with observational data by use of traditional multivariable survival analysis, propensity score adjustment, and instrumental variable analysis. Results Prostate cancer patients receiving conservative management were more likely to be older, nonwhite, and single and to have more advanced disease than patients receiving radical prostatectomy. In a multivariable survival analysis, conservative management was associated with greater risk of prostate cancer-specific mortality ( hazard ratio [HR] = 1.59, 95% confidence interval [CI] = 1.27 to 2.00) and all-cause mortality ( HR = 1.47, 95% CI = 1.35 to 1.59) than radical prostatectomy. Propensity score adjustments resulted in similar patient characteristics across treatment groups, although survival results were similar to traditional multivariable survival analyses. Results for the same comparison from the instrumental variable approach, which theoretically equalizes both observed and unobserved patient characteristics across treatment groups, differed from the traditional multivariable and propensity score results but were consistent with findings from the subset of elderly patient with early-stage disease in the trial (ie, conservative management vs radical prostatectomy: for prostate cancer-specific mortality, HR = 0.73, 95% CI = 0.08 to 6.73; for all-cause mortality, HR = 1.09, 95% CI = 0.46 to 2.59). Conclusion Instrumental variable analysis may be a useful technique in comparative effectiveness studies of cancer treatments if an acceptable instrument can be identified.
引用
收藏
页码:1780 / 1793
页数:14
相关论文
共 55 条
[1]   13-year outcomes following treatment for clinically localized prostate cancer in a population based cohort [J].
Albertsen, Peter C. ;
Hanley, James A. ;
Penson, David F. ;
Barrows, George ;
Fine, Judith .
JOURNAL OF UROLOGY, 2007, 177 (03) :932-936
[2]  
[Anonymous], 2009, IN NAT PRIOR COMP EF, DOI DOI 10.17226/12648
[3]  
[Anonymous], USE PROPENSITY SCORE
[4]  
[Anonymous], 2009, CANC FACTS FIG 2009
[5]   Use of instrumental variables in the presence of heterogeneity and self-selection: An application to treatments of breast cancer patients [J].
Basu, Anirban ;
Heckman, James J. ;
Navarro-Lozano, Salvador ;
Urzua, Sergio .
HEALTH ECONOMICS, 2007, 16 (11) :1133-1157
[6]   Radical prostatectomy versus watchful waiting in early prostate cancer [J].
Bill-Axelson, A ;
Holmberg, L ;
Ruutu, M ;
Häggman, M ;
Andersson, SO ;
Bratell, S ;
Spångberg, A ;
Busch, C ;
Nordling, S ;
Garmo, H ;
Palmgren, J ;
Adami, HO ;
Norlén, BJ ;
Johansson, JE .
NEW ENGLAND JOURNAL OF MEDICINE, 2005, 352 (19) :1977-1984
[7]   Radical prostatectomy versus watchful waiting in localized prostate cancer:: the Scandinavian Prostate Cancer Group-4 randomized trial [J].
Bill-Axelson, Anna ;
Holmberg, Lars ;
Filen, Frej ;
Ruutu, Mirja ;
Garmo, Hans ;
Busch, Christer ;
Nordling, Stig ;
Haggman, Michael ;
Andersson, Swen-Olof ;
Bratell, Stefan ;
Spangberg, Anders ;
Palmgren, Juni ;
Adami, Hans-Olov ;
Johansson, Jan-Erik .
JOURNAL OF THE NATIONAL CANCER INSTITUTE, 2008, 100 (16) :1144-1154
[8]   PROBLEMS WITH INSTRUMENTAL VARIABLES ESTIMATION WHEN THE CORRELATION BETWEEN THE INSTRUMENTS AND THE ENDOGENOUS EXPLANATORY VARIABLE IS WEAK [J].
BOUND, J ;
JAEGER, DA ;
BAKER, RM .
JOURNAL OF THE AMERICAN STATISTICAL ASSOCIATION, 1995, 90 (430) :443-450
[9]   Evaluating the validity of an instrumental variable study of neuroleptics - Can between-physician differences in prescribing patterns be used to estimate treatment effects? [J].
Brookhart, M. Alan ;
Rassen, Jeremy A. ;
Wang, Philip S. ;
Dormuth, Colin ;
Mogun, Helen ;
Schneeweiss, Sebastian .
MEDICAL CARE, 2007, 45 (10) :S116-S122
[10]   Was breast conserving surgery underutilized for early stage breast cancer? Instrumental variables evidence for stage II patients from Iowa [J].
Brooks, JM ;
Chrischilles, EA ;
Scott, SD ;
Chen-Hardee, SS .
HEALTH SERVICES RESEARCH, 2003, 38 (06) :1385-1402