Survival Analyses in MerQur: The Full Repertoire of Time-to-Event Data

Authors

  • Ömer K. Örücü Author

DOI:

https://doi.org/10.53463/merqur.20260452

Keywords:

survival analysis, Kaplan-Meier, Cox regresyon, frailty

Abstract

Survival analysis is a family of statistical methods that handles time-to-event data: an event whose occurrence time is to be observed (death, disease recurrence, machine failure, species establishment, customer churn) and censored units whose event has not yet occurred by the end of follow-up. Classical regression cannot correctly handle censoring; survival analysis is therefore a separate methodological tradition. This study introduces in detail the 8 analyses offered in MerQur’s Survival category: Kaplan-Meier survival analysis, Cox proportional-hazards regression, Parametric Survival (AFT — Weibull/lognormal/log-logistic), Competing Risks (Fine-Gray), Time-dependent Cox (time-varying covariates), Survey-PHREG (complex-sample weighted Cox), Interval-Censored survival, and Shared-Frailty Cox (Cox with random effects). For each: (i) mathematical basis, (ii) types of censoring (right, left, interval) and application context, (iii) form fields and options in MerQur, (iv) reported statistics (hazard ratio, 95% CI, median survival, RMST), and (v) interpretation guidance for a typical research question. The proportional-hazards assumption of the Cox model is automatically tested via Schoenfeld residuals; the most appropriate distribution for parametric AFT is selected by AIC comparison. Within the competing-risks framework, the Fine-Gray subdistribution hazard provides different information from classical Cox. MerQur offers an integrated tool environment in Turkish for survival research ranging from medical research to forest ecology, from financial survival to technical reliability.

References

Aalen, O. O. (1989). A linear regression model for the analysis of life times. Statistics in Medicine, 8(8), 907–925. https://doi.org/10.1002/sim.4780080803

Andersen, P. K., Borgan, Ø., Gill, R. D., & Keiding, N. (1993). Statistical models based on counting processes. Springer.

Breslow, N. E. (1974). Covariance analysis of censored survival data. Biometrics, 30(1), 89–99. https://doi.org/10.2307/2529620

Cox, D. R. (1972). Regression models and life-tables. Journal of the Royal Statistical Society: Series B, 34(2), 187–202. https://doi.org/10.1111/j.2517-6161.1972.tb00899.x

Fine, J. P., & Gray, R. J. (1999). A proportional hazards model for the subdistribution of a competing risk. Journal of the American Statistical Association, 94(446), 496–509. https://doi.org/10.1080/01621459.1999.10474144

Gómez, G., Calle, M. L., Oller, R., & Langohr, K. (2009). Tutorial on methods for interval-censored data and their implementations in R. Statistical Modelling, 9(4), 259–297. https://doi.org/10.1177/1471082X0900900402

Grambsch, P. M., & Therneau, T. M. (1994). Proportional hazards tests and diagnostics based on weighted residuals. Biometrika, 81(3), 515–526. https://doi.org/10.1093/biomet/81.3.515

Hougaard, P. (2000). Analysis of multivariate survival data. Springer.

Kalbfleisch, J. D., & Prentice, R. L. (2002). The statistical analysis of failure time data (2nd ed.). Wiley.

Kaplan, E. L., & Meier, P. (1958). Nonparametric estimation from incomplete observations. Journal of the American Statistical Association, 53(282), 457–481. https://doi.org/10.2307/2281868

Kleinbaum, D. G., & Klein, M. (2012). Survival analysis: A self-learning text (3rd ed.). Springer.

Lin, D. Y. (2000). On fitting Cox’s proportional hazards models to survey data. Biometrika, 87(1), 37–47. https://doi.org/10.1093/biomet/87.1.37

Lumley, T. (2004). Analysis of complex survey samples. Journal of Statistical Software, 9(8), 1–19. https://doi.org/10.18637/jss.v009.i08

Royston, P., & Parmar, M. K. B. (2002). Flexible parametric proportional-hazards and proportional-odds models for censored survival data. Statistics in Medicine, 21(15), 2175–2197. https://doi.org/10.1002/sim.1203

Schoenfeld, D. (1982). Partial residuals for the proportional hazards regression model. Biometrika, 69(1), 239–241. https://doi.org/10.1093/biomet/69.1.239

Therneau, T. M., & Grambsch, P. M. (2000). Modeling survival data: Extending the Cox model. Springer. https://doi.org/10.1007/978-1-4757-3294-8

Turnbull, B. W. (1976). The empirical distribution function with arbitrarily grouped, censored and truncated data. Journal of the Royal Statistical Society: Series B, 38(3), 290–295.

Vaupel, J. W., Manton, K. G., & Stallard, E. (1979). The impact of heterogeneity in individual frailty on the dynamics of mortality. Demography, 16(3), 439–454. https://doi.org/10.2307/2061224

Wei, L. J. (1992). The accelerated failure time model: A useful alternative to the Cox regression model in survival analysis. Statistics in Medicine, 11(14–15), 1871–1879. https://doi.org/10.1002/sim.4780111409

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Published

2026-05-18

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Editorial