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Modeling Survival Data: Extending the Cox Model
11 Aug 2000-
TL;DR: A Cox Model-based approach was used to estimate the Survival and Hazard Functions and the results confirmed the need for further investigation into the role of natural disasters in shaping survival rates.
Abstract: Introduction.- Estimating the Survival and Hazard Functions.- The Cox Model.- Residuals.- Functional Form.- Testing Proportional Hazards.- Influence.- Multiple Events per Subject.- Frailty Models.- Expected Survival.
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TL;DR: The longitudinal glomerular filtration rate was estimated among 1,120,295 adults within a large, integrated system of health care delivery in whom serum creatinine had been measured between 1996 and 2000 and who had not undergone dialysis or kidney transplantation.
Abstract: Background End-stage renal disease substantially increases the risks of death, cardiovascular disease, and use of specialized health care, but the effects of less severe kidney dysfunction on these outcomes are less well defined. Methods We estimated the longitudinal glomerular filtration rate (GFR) among 1,120,295 adults within a large, integrated system of health care delivery in whom serum creatinine had been measured between 1996 and 2000 and who had not undergone dialysis or kidney transplantation. We examined the multivariable association between the estimated GFR and the risks of death, cardiovascular events, and hospitalization. Results The median follow-up was 2.84 years, the mean age was 52 years, and 55 percent of the group were women. After adjustment, the risk of death increased as the GFR decreased below 60 ml per minute per 1.73 m2 of body-surface area: the adjusted hazard ratio for death was 1.2 with an estimated GFR of 45 to 59 ml per minute per 1.73 m2 (95 percent confidence interval, 1....
9,642 citations
TL;DR: In this pooled analysis of individual data from 9 selected cohorts, gait speed was associated with survival in older adults and predicted survival was as accurate as predicted based on age, sex, use of mobility aids, and self-reported function.
Abstract: Context Survival estimates help individualize goals of care for geriatric patients, but life tables fail to account for the great variability in survival. Physical performance measures, such as gait speed, might help account for variability, allowing clinicians to make more individualized estimates. Objective To evaluate the relationship between gait speed and survival. Design, Setting, and Participants Pooled analysis of 9 cohort studies (collected between 1986 and 2000), using individual data from 34 485 community-dwelling older adults aged 65 years or older with baseline gait speed data, followed up for 6 to 21 years. Participants were a mean (SD) age of 73.5 (5.9) years; 59.6%, women; and 79.8%, white; and had a mean (SD) gait speed of 0.92 (0.27) m/s. Main Outcome Measures Survival rates and life expectancy. Results There were 17 528 deaths; the overall 5-year survival rate was 84.8% (confidence interval [CI], 79.6%-88.8%) and 10-year survival rate was 59.7% (95% CI, 46.5%-70.6%). Gait speed was associated with survival in all studies (pooled hazard ratio per 0.1 m/s, 0.88; 95% CI, 0.87-0.90; P Conclusion In this pooled analysis of individual data from 9 selected cohorts, gait speed was associated with survival in older adults.
3,393 citations
TL;DR: In patients with type 2 diabetes at high risk for cardiovascular events, targeting a systolic blood pressure of less than 120 mm HG, as compared with less than 140 mm Hg, did not reduce the rate of a composite outcome of fatal and nonfatal major cardiovascular events.
Abstract: After 1 year, the mean systolic blood pressure was 1193 mm Hg in the intensivetherapy group and 1335 mm Hg in the standard-therapy group The annual rate of the primary outcome was 187% in the intensive-therapy group and 209% in the standard-therapy group (hazard ratio with intensive therapy, 088; 95% confidence interval [CI], 073 to 106; P = 020) The annual rates of death from any cause were 128% and 119% in the two groups, respectively (hazard ratio, 107; 95% CI, 085 to 135; P = 055) The annual rates of stroke, a prespecified secondary outcome, were 032% and 053% in the two groups, respectively (hazard ratio, 059; 95% CI, 039 to 089; P = 001) Serious adverse events attributed to antihypertensive treatment occurred in 77 of the 2362 participants in the intensive-therapy group (33%) and 30 of the 2371 participants in the standard-therapy group (13%) (P<0001) Conclusions In patients with type 2 diabetes at high risk for cardiovascular events, targeting a systolic blood pressure of less than 120 mm Hg, as compared with less than 140 mm Hg, did not reduce the rate of a composite outcome of fatal and nonfatal major cardiovascular events (ClinicalTrialsgov number, NCT00000620)
3,107 citations
TL;DR: Survivors of childhood cancer have a high rate of illness owing to chronic health conditions, including severe, disabling, or life-threatening conditions or death due to a chronic condition.
Abstract: Background Only a few small studies have assessed the long-term morbidity that follows the treatment of childhood cancer. We determined the incidence and severity of chronic health conditions in adult survivors. Methods The Childhood Cancer Survivor Study is a retrospective cohort study that tracks the health status of adults who received a diagnosis of childhood cancer between 1970 and 1986 and compares the results with those of siblings. We calculated the frequencies of chronic conditions in 10,397 survivors and 3034 siblings. A severity score (grades 1 through 4, ranging from mild to life-threatening or disabling) was assigned to each condition. Cox proportional-hazards models were used to estimate hazard ratios, reported as relative risks and 95% confidence intervals (CIs), for a chronic condition. Results Survivors and siblings had mean ages of 26.6 years (range, 18.0 to 48.0) and 29.2 years (range, 18.0 to 56.0), respectively, at the time of the study. Among 10,397 survivors, 62.3% had at least one chronic condition; 27.5% had a severe or life-threatening condition (grade 3 or 4). The adjusted relative risk of a chronic condition in a survivor, as compared with siblings, was 3.3 (95% CI, 3.0 to 3.5); for a severe or life-threatening condition, the risk was 8.2 (95% CI, 6.9 to 9.7). Among survivors, the cumulative incidence of a chronic health condition reached 73.4% (95% CI, 69.0 to 77.9) 30 years after the cancer diagnosis, with a cumulative incidence of 42.4% (95% CI, 33.7 to 51.2) for severe, disabling, or life-threatening conditions or death due to a chronic condition. Conclusions Survivors of childhood cancer have a high rate of illness owing to chronic health conditions.
2,897 citations