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Bronchodilator response per the Pellegrino 2005 standard

Source: R/interpretation_2005.R
pft_bdr_2005.Rd

Classifies bronchodilator response (BDR) by the Pellegrino et al. ERJ 2005 dual criterion: significant if both the relative change from baseline is at least 12% AND the absolute change is at least 200 mL. Replaced in 2022 by pft_bdr()'s simpler "> 10% of predicted" rule.

Usage

pft_bdr_2005(pre, post)

Arguments

pre, post

Numeric vectors of pre- and post-bronchodilator measurements, in litres, same length.

Value

A data frame with one row per input observation and three columns: pct_change (i.e. (post - pre) / pre * 100), abs_change (i.e. post - pre in litres), and is_significant (logical, TRUE when pct_change > 12 AND abs_change > 0.2, both inequalities strict per the paper's wording on p. 959: "(>12% of control and >200 mL)"). NA propagates wherever either of pre / post is NA.

Column naming

This function's pct_change column is percent-of-baseline change (the 2005 criterion). The 2022 pft_bdr() emits a similarly-named but different column, pct_pred_change, which is percent-of-predicted change ((post - pre) / predicted * 100, the 2022 criterion). The two functions deliberately use distinct column names so a result frame can carry both without ambiguity.

References

Pellegrino R, Viegi G, Brusasco V, et al. Interpretative strategies for lung function tests. Eur Respir J. 2005;26(5):948-968. doi:10.1183/09031936.05.00035205 . Criterion stated in the "Bronchodilator response" section (p. 958) and disambiguated on p. 959.

See also

pft_bdr() for the current Stanojevic 2022 criterion (>10% of predicted). Unlike the 2022 form, the 2005 version does not need the patient's predicted FEV1 / FVC – only the pre and post measurements.

Examples

pft_bdr_2005(pre = c(2.5, 2.0), post = c(2.8, 2.1))
#> # A tibble: 2 × 3
#>   pct_change abs_change is_significant
#>        <dbl>      <dbl> <lgl>         
#> 1      12         0.300 FALSE         
#> 2       5.00      0.100 FALSE         
# -> first row significant (>=12% AND >=200 mL),
#    second row not (only 5% and 100 mL increase)