ArticleEpidemiology (Cambridge, Mass.)2015
Comparative Effectiveness of Oxaliplatin Versus 5-flourouricil in Older Adults: An Instrumental Variable Analysis.
Article in Epidemiology (Cambridge, Mass.), 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 9 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
9 citing papers in PubMed, 20 citations in OpenAlex.
- Noninterventional studies in the COVID-19 era: methodological considerations for study design and analysis.Journal of clinical epidemiology · 2023Article
- Geriatric oncology health services research: Cancer and Aging Research Group infrastructure core.Journal of geriatric oncology · 2020Article
- Long-term use of hydrocodone vs. oxycodone in primary care.Drug and alcohol dependence · 2019Article
- Estimating Causal Effects of New Treatments Despite Self-Selection: The Case of Experimental Medical Treatments.Journal of causal inference · 2019Article
- Methodologic limitations of prescription opioid safety research and recommendations for improving the evidence base.Pharmacoepidemiology and drug safety · 2019Review
- Surveillance, Epidemiology, and End Results (SEER) and SEER-Medicare Databases: Use in Clinical Research for Improving Colorectal Cancer Outcomes.Clinics in colon and rectal surgery · 2019Review
- On two-stage estimation of structural instrumental variable models.Biometrika · 2017Article
- Instrumental Variable Analyses in Pharmacoepidemiology: What Target Trials Do We Emulate?Current epidemiology reports · 2017Review
- How Does Outcomes Research Help Advance Our Knowledge of Patient Outcomes in Hepatopancreaticobiliary Surgery?Journal of gastrointestinal surgery : official journal of the Society for Surgery of the Alimentary Tract · 2016Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors at 3 institutions in 2 countries.
Funding
Abstract
backgroundOxaliplatin was rapidly adopted for treatment of stage III colon cancer after FDA approval in November 2004, thus providing an opportunity to use calendar time as an instrumental variable in nonexperimental comparative effectiveness research. Assuming instrument validity, instrumental variable analyses account for unmeasured confounding and are particularly valuable in sub-populations of unresolved effectiveness, such as older individuals.
methodsWe examined stage III colon cancer patients ages 65+ years initiating chemotherapy between 2003 and 2008 using US population-based cancer registry data linked with Medicare claims (N = 3,660). Risk differences for all-cause mortality were derived from Kaplan-Meier survival curves. We examined instrumental variable strength and compared risk differences with propensity score estimates.
resultsCalendar time greatly affected oxaliplatin receipt. The calendar time instrument compared patients treated from January 2003 through September 2004 (N = 1,449) with those treated from March 2005 through May 2007 (N = 1,432), resulting in 54% compliance. The 1-, 2-, and 3-year local average treatment effect of the risk differences per 100 patients in the "compliers" (95% confidence intervals) were -4.6 (-8.2, -0.44), -6.3 (-12, -0.16), and -9.2 (-15, -2.5), respectively. Corresponding propensity score-matched results were -1.9 (-4.0, 0.2), -3.4 (-6.2, -0.05), and -4.3 (-7.5, -0.96).
conclusionsInstrumental variable and propensity score analyses both indicate better survival among patients treated with oxaliplatin. As these results are based on different populations and assumptions, the instrumental variable analysis adds to evidence of oxaliplatin's effectiveness in older adults, who bear the greatest burden of colon cancer yet were underrepresented in clinical trials. In nonexperimental comparative effectiveness research of rapidly emerging therapies, the potential to use calendar time as an instrumental variable is worth consideration.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.