NEWS

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survkit 0.1.0

First public release. The registry-dispatched facade of the development scaffold gains its value layer: the decision-relevant estimands and the cross-method consistency checks that make survkit a methodology rather than a wrapper.

Breaking changes

• survkit_tidy() no longer exponentiates a parametric fit's baseline parameters into a meaningless ratio, and it now labels each covariate effect by scale. The output gains a component column ("covariate" / "auxiliary") and a ratio_type column ("HR" / "TR" / "OR" / probit).

  # before: shape and scale were listed as covariates with a bogus "ratio"
  #   term  estimate  ratio
  #   scale 6.27      531.0        <- exponentiated log-scale intercept
  #   sex   0.38      1.47         <- a time ratio, unlabelled
  
  # after: auxiliaries are separated, covariates carry their ratio type
  #   term  component  estimate  ratio_type  ratio
  #   scale auxiliary  6.27      <NA>        NA
  #   sex   covariate  0.38      TR          1.47
  

• survkit_curve() returns its predicted quantity in a column named value (was survival), because the function now predicts hazard, cumulative hazard and quantiles as well as survival.

New features

• survkit_triangulate() fits the same data under several methods and reads their relative spread on the restricted mean (and, optionally, survival at a landmark) as a model-misspecification signal.
• survkit_rmst() computes the restricted mean survival time to a horizon, with the backend's interval for parametric fits and the survival package's standard error for Cox-family and non-parametric fits.
• survkit_cuminc() gives the Aalen-Johansen cumulative incidence of each competing event.
• survkit_score() scores predictions with Harrell's concordance and the inverse-probability-of-censoring-weighted Brier score and its index of prediction accuracy.
• survkit_contract() and survkit_validate_method() expose and check the registry conformance contract every fit closure must honour.
• New methods in the registry: km (Kaplan-Meier / Nelson-Aalen non-parametric baseline) and cox_ridge (ridge-penalised Cox for the few-events regime).
• survkit_curve() gains a type argument ("survival", "hazard", "cumhaz", "quantile").
• as_survkit_manifest() now emits a genuine per-draw survival ensemble for parametric, spline and cure fits (the draws and the survival share one sample); Cox-family fits emit the maximum-likelihood curve marked draw = 0.
• survkit() gains an on_underpowered = c("warn", "abstain") argument. "warn" preserves the historical behaviour (fit anyway, with a warning); "abstain" declines to fit an under-powered model and instead returns a [survkit_refusal()] -- a typed, classed token (c("survkit_refusal", "orchestra_refusal", "error", "condition")) recognisable to a leader-side gate via is_orchestra_decline(), rather than a bare warning() plus a fitted model regardless of the power gate's verdict.

Minor improvements and fixes

• The power gate returns "unknown" for a multi-state (competing-risks) response rather than pooling the competing events into one misleading count.
• Cox-family fits retain their model frame (model = TRUE), so survival curves and scoring on new data work reliably.
• survkit_fit carries ratio_type and aux_pars so the tidier can separate covariate effects from baseline parameters for any backend.

Documentation

• Vignette (Getting started with survkit) gains three figures with captions and interpretive prose: a Kaplan-Meier curve by age group, a stacked cumulative-incidence plot for the competing-risks example, and a "triangulation fan" plotting each method's restricted mean survival time against the disagreement band. It also states the governing equations for the events-per-variable gate, the restricted mean survival time and the IPCW Brier score, each with its source citation, and rewords the triangulation section so it no longer asserts that a flagged disagreement proves model misspecification (it can also arise from comparing different estimands, which the vignette now says explicitly).
• README.md leads with the package's purpose in the first lines, and every code snippet is now self-contained and runnable end-to-end on survival::lung / survival::mgus2 (the Fine-Gray, small-sample-gate and scoring snippets previously referenced undefined objects).
• Roxygen: several @titles rewritten as sentences/imperatives rather than noun phrases (survkit_power, survkit_fit, survkit_manifest, survkit_contract, survkit_cuminc, survkit_rmst, survkit_curve); @examples added for survkit_fit, survkit_manifest and the predict method on a fit (previously undocumented by example); @references added to survkit_power and survkit_score; governing-equation @details added to survkit_rmst and survkit_score.