Lung Capacity Predicted Values (Spirometry Reference) mechanism

Model scope

The arithmetic fixtures verify only ratio and percentage post-processing using explicitly supplied provisional reference values. They do not verify the GLI-2012 demographic prediction itself. Before PASS, supply the authoritative GLI-2012 coefficient/table dataset, source/version, ethnic-group mapping, LMS equation including z=0 convention, valid ranges, interpolation rules, missing-data behavior, rounding policy, and an explicit decision on whether %predicted for FEV1/FVC is offered.

• The specification names GLI-2012 but does not provide the required GLI-2012 LMS coefficients, spline knots, coefficient version, or calculation algorithm, so the claimed predictions cannot be independently reproduced from this specification.
• GLI-2012 is ordinarily implemented with sex-, age-, height-, and ethnic-group-specific L, M, and S parameters and z-score equations; a generic lookup-table description is insufficient unless the exact table and interpolation rules are supplied.
• The permitted ethnicity categories and mapping are unspecified. GLI-2012 uses defined reference groups, and an arbitrary ethnicity label or race/ethnicity mapping can produce materially different results.
• The specification does not state whether age is decimal years or completed years, whether height is standing height in centimetres, or which sex definition and valid age range are used.
• It is ambiguous whether predicted FEV1/FVC means the quotient of predicted FEV1 divided by predicted FVC or a separately predicted GLI-2012 ratio/z-score quantity.
• %predicted is not generally a clinically appropriate summary for FEV1/FVC; the ratio is commonly interpreted with its own reference distribution or z-score, not simply as a percentage of predicted ratio.

Units and conventions

• Age is assumed to be in years and within the validated GLI-2012 range of approximately 3 through 95 years.
• Height is assumed to be standing height in centimetres; no automatic conversion from inches is assumed.
• FVC and FEV1 are assumed to be in litres (BTPS-adjusted spirometric values).
• Ratios are dimensionless and are reported here as a decimal rather than a percentage.
• The provisional table rows below are explicit test fixtures for arithmetic and post-processing only; they are not a substitute for the missing official GLI-2012 coefficient tables.

Inspectable vector

One of 4 source-bound review vectors:

{
  "inputs": {
    "age_years": 25,
    "height_cm": 180,
    "sex": "male",
    "ethnicity": "Caucasian",
    "measured_FVC_L": 5,
    "measured_FEV1_L": 4
  },
  "expected_outputs": {
    "predicted_FVC_L": 5.5,
    "predicted_FEV1_L": 4.4,
    "predicted_FEV1_FVC_ratio": 0.8,
    "FVC_percent_predicted": 90.91,
    "FEV1_percent_predicted": 90.91
  },
  "reference_data": {
    "predicted_FVC_L": 5.5,
    "predicted_FEV1_L": 4.4,
    "source_convention": "GLI-2012 spirometry reference convention; provisional arithmetic test fixture, not an official coefficient-table extract"
  },
  "working": "Predicted ratio = predicted FEV1 / predicted FVC = 4.4 / 5.5 = 0.800000. FVC %predicted = 5.0 / 5.5 x 100 = 0.9090909 x 100 = 90.91%. FEV1 %predicted = 4.0 / 4.4 x 100 = 0.9090909 x 100 = 90.91%."
}

Failure boundary

BREAK_CLAIMED · SELF_FLAGGED

The specification cannot produce numerical predicted FVC, FEV1, or ratio outputs because the required GLI-2012 coefficient tables and exact validity/switch definitions are missing. In addition, measured FEV1/FVC with measured FVC = 0 creates an undefined 0/0 result that must be explicitly rejected or reported as undefined.

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche7/tranche7-results.json
• BOUNDARY_HAZARD_CATALOG.json