BMJ 1998;317:1572-1580 ( 5 December )

Clinical review

Statistics Notes

Survival probabilities (the Kaplan-Meier method)

J Martin Bland, professor of medical statistics, ^a Douglas G Altman, head. ^b

^a Department of Public Health Sciences, St George's Hospital Medical School, London SW17 0RE, ^b ICRF Medical Statistics Group, Centre for Statistics in Medicine, Institute of Health Sciences, Oxford OX3 7LF

Correspondence to: Professor Bland

The first 150 words of the full text of this article appear below.

As we have observed,¹ analysis of survival data requires special techniques because some observations are censored as the event of interest has not occurred for all patients. For example, when patients are recruited over two years one recruited at the end of the study may be alive at one year follow up, whereas one recruited at the start may have died after two years. The patient who died has a longer observed survival than the one who still survives and whose ultimate survival time is unknown.

The table shows data from a study of conception in subfertile women.² The event is conception, and women "survived" until they conceived. One woman conceived after 16 months (menstrual cycles), whereas several were followed for shorter time periods during which they did not conceive; their time to conceive was thus censored.

Table Removed (Available Only in the Full Text)

We wish to estimate the proportion surviving (not having conceived) by any given time, . . . [Full text of this article]

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    StumbleUpon    Technorati    What's this?

Relevant Article

Four layer bandage compared with short stretch bandage for venous leg ulcers: systematic review and meta-analysis of randomised controlled trials with data from individual patients

Susan O’Meara, Jayne Tierney, Nicky Cullum, J Martin Bland, Peter J Franks, Trevor Mole, and Mark Scriven
BMJ 2009 338: b1344. [Abstract] [Full Text] [PDF]

This article has been cited by other articles:

• Jovic-Vranes, A., Bjegovic-Mikanovic, V., Marinkovic, J. (2009). Functional health literacy among primary health-care patients: data from the Belgrade pilot study. J Public Health (Oxf) 31: 490-495 [Abstract] [Full text]  
• Tremlett, H., Yousefi, M., Devonshire, V., Rieckmann, P., Zhao, Y., On behalf of the UBC Neurologists, (2009). Impact of multiple sclerosis relapses on progression diminishes with time. Neurology 73: 1616-1623 [Abstract] [Full text]  
• Moraes, R. B., Czepielewski, M. A. (2009). Corticosteroid Therapy for Severe Sepsis and Septic Shock. JAMA 302: 1643-1644 [Full text]  
• Cheang, M. C. U., Chia, S. K., Voduc, D., Gao, D., Leung, S., Snider, J., Watson, M., Davies, S., Bernard, P. S., Parker, J. S., Perou, C. M., Ellis, M. J., Nielsen, T. O. (2009). Ki67 Index, HER2 Status, and Prognosis of Patients With Luminal B Breast Cancer. JNCI J Natl Cancer Inst 101: 736-750 [Abstract] [Full text]  
• O'Meara, S., Tierney, J., Cullum, N., Bland, J M., Franks, P. J, Mole, T., Scriven, M. (2009). Four layer bandage compared with short stretch bandage for venous leg ulcers: systematic review and meta-analysis of randomised controlled trials with data from individual patients. BMJ 338: b1344-b1344 [Abstract] [Full text]  
• Malizia, B. A., Hacker, M. R., Penzias, A. S. (2009). Cumulative Live-Birth Rates after In Vitro Fertilization. NEJM 360: 236-243 [Abstract] [Full text]  
• Joshi, A. Y., Iyer, V. N., Hagan, J. B., Sauver, J. L. St., Boyce, T. G. (2009). Incidence and Temporal Trends of Primary Immunodeficiency: A Population-Based Cohort Study. Mayo Clin Proc. 84: 16-22 [Abstract] [Full text]  
• Kadhiravan, T., Wig, N., Renuka, K., Kapil, A., Kabra, S. K., Misra, A. (2008). Is nalidixic acid resistance linked to clinical virulence in Salmonella enterica serovar Typhi infections?. J Med Microbiol 57: 1046-1048 [Full text]  
• Sherer, M, Struchen, M A, Yablon, S A, Wang, Y, Nick, T G (2008). Comparison of indices of traumatic brain injury severity: Glasgow Coma Scale, length of coma and post-traumatic amnesia. J. Neurol. Neurosurg. Psychiatry 79: 678-685 [Abstract] [Full text]  
• Ajani, J. A. (2008). In Reply. JCO 26: 2236-2237 [Full text]  
• Cheang, M. C.U., Voduc, D., Bajdik, C., Leung, S., McKinney, S., Chia, S. K., Perou, C. M., Nielsen, T. O. (2008). Basal-Like Breast Cancer Defined by Five Biomarkers Has Superior Prognostic Value than Triple-Negative Phenotype. Clin. Cancer Res. 14: 1368-1376 [Abstract] [Full text]  
• Royston, P., Parmar, M. K. B., Altman, D. G. (2008). Visualizing Length of Survival in Time-to-Event Studies: A Complement to Kaplan Meier Plots. JNCI J Natl Cancer Inst 100: 92-97 [Abstract] [Full text]  
• Younes, M., Ostrowski, M., Atkar, R., Laprairie, J., Siemens, A., Hanly, P. (2007). Mechanisms of breathing instability in patients with obstructive sleep apnea. J. Appl. Physiol. 103: 1929-1941 [Abstract] [Full text]  
• Du, Y., Cullum, I., Illidge, T. M., Ell, P. J. (2007). Fusion of Metabolic Function and Morphology: Sequential [18F]Fluorodeoxyglucose Positron-Emission Tomography/Computed Tomography Studies Yield New Insights Into the Natural History of Bone Metastases in Breast Cancer. JCO 25: 3440-3447 [Abstract] [Full text]  
• Palma, B. D., Gabriel, A. Jr., Colugnati, F. A. B., Tufik, S. (2006). Effects of sleep deprivation on the development of autoimmune disease in an experimental model of systemic lupus erythematosus. Am. J. Physiol. Regul. Integr. Comp. Physiol. 291: R1527-R1532 [Abstract] [Full text]  
• Kissane, D. W., McKenzie, M., Bloch, S., Moskowitz, C., McKenzie, D. P., O'Neill, I. (2006). Family Focused Grief Therapy: A Randomized, Controlled Trial in Palliative Care and Bereavement. Am. J. Psychiatry 163: 1208-1218 [Abstract] [Full text]  
• Carey, L. A., Perou, C. M., Livasy, C. A., Dressler, L. G., Cowan, D., Conway, K., Karaca, G., Troester, M. A., Tse, C. K., Edmiston, S., Deming, S. L., Geradts, J., Cheang, M. C. U., Nielsen, T. O., Moorman, P. G., Earp, H. S., Millikan, R. C. (2006). Race, breast cancer subtypes, and survival in the Carolina Breast Cancer Study.. JAMA 295: 2492-2502 [Abstract] [Full text]  
• Collantes-Fernandez, E., Lopez-Perez, I., Alvarez-Garcia, G., Ortega-Mora, L. M. (2006). Temporal Distribution and Parasite Load Kinetics in Blood and Tissues during Neospora caninum Infection in Mice. Infect. Immun. 74: 2491-2494 [Abstract] [Full text]  
• Artes, P. H., Nicolela, M. T., LeBlanc, R. P., Chauhan, B. C. (2005). Visual Field Progression in Glaucoma: Total Versus Pattern Deviation Analyses. IOVS 46: 4600-4606 [Abstract] [Full text]  
• Stead, L. G., Gilmore, R. M., Decker, W. W., Weaver, A. L., Brown, R. D. Jr (2005). Initial emergency department blood pressure as predictor of survival after acute ischemic stroke. Neurology 65: 1179-1183 [Abstract] [Full text]  
• Wagena, E. J., Knipschild, P. G., Huibers, M. J. H., Wouters, E. F. M., van Schayck, C. P. (2005). Efficacy of Bupropion and Nortriptyline for Smoking Cessation Among People at Risk for or With Chronic Obstructive Pulmonary Disease. Arch Intern Med 165: 2286-2292 [Abstract] [Full text]  
• Robertson, M. C., Campbell, A. J., Herbison, P. (2005). Statistical Analysis of Efficacy in Falls Prevention Trials. Journals of Gerontology Series A: Biological Sciences and Medical Sciences 60: 530-534 [Abstract] [Full text]  
• Nuckel, H., Rebmann, V., Durig, J., Duhrsen, U., Grosse-Wilde, H. (2005). HLA-G expression is associated with an unfavorable outcome and immunodeficiency in chronic lymphocytic leukemia. Blood 105: 1694-1698 [Abstract] [Full text]  
• Sinha, R. K., Dungy, D. S., Yeon, H. B. (2004). Primary Total Hip Arthroplasty with a Proximally Porous-Coated Femoral Stem. JBJS 86: 1254-1261 [Abstract] [Full text]  
• Bland, J M., Altman, D. G (2004). The logrank test. BMJ 328: 1073-1073 [Full text]  
• Chinn, S. (2001). Statistics for the European Respiratory Journal. Eur Respir J 18: 393-401 [Abstract] [Full text]  
• George, T. P., Ziedonis, D. M., Feingold, A., Pepper, W. T., Satterburg, C. A., Winkel, J., Rounsaville, B. J., Kosten, T. R. (2000). Nicotine Transdermal Patch and Atypical Antipsychotic Medications for Smoking Cessation in Schizophrenia. Am. J. Psychiatry 157: 1835-1842 [Abstract] [Full text]  
• Leonard, H, Derrick, G, O'Sullivan, J, Wren, C (2000). Natural and unnatural history of pulmonary atresia. Heart 84: 499-503 [Abstract] [Full text]  

Rapid Responses:

Read all Rapid Responses

Survival Analysis results have to be appropriately shown

Bruno Mario Cesana
bmj.com, 30 Dec 1998 [Full text]

Online poll

Find out more>>