Skip to Main Content


  • Image not available.When research involves time-related variables, such as survival and recurrence, we generally do not know the outcome for all patients at the time the study is published, so these outcomes are called censored.
  • Image not available.Observations are doubly censored when not all patients enter the study at the same time.
  • Image not available.An example of why special methods are needed to analyze survival data helps illustrate the logic behind them.
  • Image not available.Life table or actuarial methods were developed to show survival curves; although generally surpassed by Kaplan–Meier curves, they occasionally appear in the literature.
  • Image not available.Survival analysis gives patients credit for how long they have been in the study, even if the outcome has not yet occurred.
  • Image not available.The Kaplan–Meier procedure is the most commonly used method to illustrate survival curves.
  • Image not available.Estimates of survival are less precise as the time from entry into the study becomes longer, because the number of patients in the study decreases.
  • Image not available.Survival curves can also be used to compare survival in two or more groups.
  • Image not available.The logrank statistic is one of the most commonly used methods to learn if two curves are significantly different.
  • Image not available.The hazard ratio is similar to the odds ratio; the difference is that the hazard ratio compares risk over time, while the odds ratio examines risk at a given time.
  • Image not available.The Mantel–Haenszel statistic is also used to compare curves, not just survival curves.
  • Image not available.Several versions of the logrank statistic exist. The logrank statistic assumes that the risk of the outcome is the constant over time.
  • Image not available.The Mantel—Haenszel statistic essentially combines a number of 2 × 2 tables for an overall measure of difference.
  • Image not available.The hazard function gives the probability that an outcome will occur in a given period, assuming that the outcome has not occurred during previous periods.
  • Image not available.The intention-to-treat principle states that subjects are analyzed in the group to which they were assigned. It minimizes bias when there are treatment crossovers or dropouts.


Presenting Problem 1


Lung cancer is the leading cause of cancer deaths in men and in women between the ages of 15 and 64 years of age. Small-cell lung cancer accounts for 20–25% of all cases of lung cancer. At the time of diagnosis, 40% of the patients with small-cell cancer have disease confined to the thorax (limited disease) and 60% have metastases outside of the thorax (extensive disease). Current standard chemotherapy for extensive disease using a combination of cisplatin and etoposide yields a median survival of 8–10 months and a 2-year survival rate of 10%. Preliminary studies using a combination of cisplatin with irinotecan resulted in a median survival of 13.2 months. For this reason, Noda and colleagues (2002) at the Japan Clinical Oncology Group conducted a prospective, randomized clinical trial to compare irinotecan plus cisplatin with etoposide plus cisplatin. The primary endpoint was overall survival. Secondary endpoints included rates of complete and overall response. A complete response was defined as the disappearance of all clinical and radiologic evidence of a tumor for ...

Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.


About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

AccessPharmacy Full Site: One-Year Subscription

Connect to the full suite of AccessPharmacy content and resources including 30+ textbooks such as Pharmacotherapy: A Pathophysiologic Approach and Goodman & Gilman's The Pharmacological Basis of Therapeutics, high-quality videos, images, and animations, interactive board review, drug and herb/supplements databases, and more.

$595 USD
Buy Now

Pay Per View: Timed Access to all of AccessPharmacy

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.