Interval-censored survival analysis for data where the exact event time is unknown but falls within an interval. Common in periodic follow-up studies, screening programs, and clinical trials with scheduled visits.
Usage
intervalsurvival(
  left_time,
  right_time,
  status_var = NULL,
  covariates = NULL,
  stratification_vars = NULL,
  model_type = "aft_weibull",
  estimation_method = "em_algorithm",
  confidence_level = 0.95,
  convergence_tolerance = 1e-04,
  max_iterations = 500,
  baseline_hazard_smooth = FALSE,
  smoothing_bandwidth = 1,
  survival_curves = TRUE,
  hazard_function = FALSE,
  model_diagnostics = TRUE,
  residual_analysis = TRUE,
  goodness_of_fit = TRUE,
  model_comparison = FALSE,
  prediction_times = "12,24,36,60",
  bootstrap_samples = 200,
  mcmc_iterations = 5000,
  mcmc_burnin = 1000,
  imputation_method = "midpoint"
)Arguments
- left_time
- Left boundary of the censoring interval 
- right_time
- Right boundary of the censoring interval 
- status_var
- Censoring status indicator variable 
- covariates
- Covariates to include in the survival model 
- stratification_vars
- Variables for stratifying the baseline hazard 
- model_type
- Model specification for interval-censored survival 
- estimation_method
- Method for parameter estimation 
- confidence_level
- Confidence level for parameter estimates 
- convergence_tolerance
- Convergence criterion for iterative algorithms 
- max_iterations
- Maximum number of algorithm iterations 
- baseline_hazard_smooth
- Whether to smooth the baseline hazard function 
- smoothing_bandwidth
- Bandwidth for baseline hazard smoothing 
- survival_curves
- Whether to plot survival curves 
- hazard_function
- Whether to plot hazard functions 
- model_diagnostics
- Whether to include model diagnostics 
- residual_analysis
- Whether to perform residual analysis 
- goodness_of_fit
- Whether to test model goodness-of-fit 
- model_comparison
- Whether to compare multiple models 
- prediction_times
- Time points for survival probability predictions 
- bootstrap_samples
- Number of bootstrap resamples 
- mcmc_iterations
- MCMC sampling iterations 
- mcmc_burnin
- MCMC burn-in period 
- imputation_method
- Imputation approach for incomplete intervals 
Value
A results object containing:
| results$instructions | a html | ||||
| results$data_summary | a html | ||||
| results$model_results | a html | ||||
| results$covariate_effects | a html | ||||
| results$survival_estimates | a html | ||||
| results$hazard_estimates | a html | ||||
| results$model_diagnostics_summary | a html | ||||
| results$goodness_of_fit_results | a html | ||||
| results$model_comparison_table | a html | ||||
| results$residual_summary | a html | ||||
| results$survival_curves_plot | an image | ||||
| results$hazard_plot | an image | ||||
| results$interval_plot | an image | ||||
| results$residual_plots | an image | ||||
| results$model_comparison_plot | an image | ||||
| results$convergence_plot | an image | 
Examples
# Example: Tumor progression between visits
intervalsurvival(
    data = oncology_data,
    left_time = last_negative_visit,
    right_time = first_positive_visit,
    covariates = c("age", "stage", "treatment"),
    model_type = "aft_weibull"
)