Table 4. Reference equations of commonly applied IOS indices for women.

Equations				Coefficients of
Percentile		Quantile value	Intercept	Age	Height	Weight
Z5 (kPa s L−1)	5%	0.23	0.6438520	−0.0002790	−0.0042285	0.0043481
	50%	0.37	0.9821420	0.0015343	−0.0059884	0.0035971
	95%	0.52	0.5504061	0.0012158	−0.0007407
R5 (kPa s L−1)	5%	0.21	0.5012224	0.0002940	−0.0037866	0.0045199
	50%	0.34	0.7887960	0.0015118	−0.0046594	0.0029768
	95%	0.49	0.1926787	0.0004133	0.0016756
R20 (kPa s L−1)	5%	0.16	0.5970057	−0.0006897	−0.0030934	0.0016623
	50%	0.26	0.4505645	0.0001251	−0.0020488	0.0017939
	95%	0.38	0.8177947	−0.0003549	−0.0025771
R5–R20 (kPa s L−1)	5%	0.02	0.1121160	0.0000864	−0.0012551	0.0016042
	50%	0.09	0.2903621	0.0010200	−0.0023036	0.0013466
	95%	0.18	0.2123060	0.0009332	−0.0015425	0.0019627
(R5–R20)/R20*100 (%)	5%	8.12	24.5324087	0.1010746	−0.3020042	0.4036923
	50%	34.13	97.7280594	0.2997946	−0.7060959	0.4350743
	95%	69.92	154.3611632	0.1383460	−0.9307476	0.7594528
X5 (kPa s L−1)	5%	−0.22	−0.5446960	−0.0018068	0.0029323
	50%	−0.12	−0.3313017	−0.0007541	0.0022090	−0.0014134
	95%	−0.07	−0.1831886	0.0003607	0.0005743
AX (Hz kPa s L−1)	5%	0.14	1.0968758	−0.0001349	−0.0077805	0.0048793
	50%	0.50	1.7909627	0.0110077	−0.0168559	0.0104360
	95%	1.47	2.7124098	0.0173679	−0.0227368	0.0152978
Fres (Hz)	5%	9.10	27.7039789	0.0406373	−0.1748922	0.1125957
	50%	15.08	29.3243480	0.1446923	−0.1998960	0.1180629
	95%	22.31	22.5107342	0.1886975	−0.0871522

Equations are derived from lung healthy women aged 45 to 89 years. Quantile regression equations for median, 5th and 95th percentile with age in years, height in cm and weight in kg (e.g., for women Z5–50% = 0.9821420+0.0015343 age–0.0059884 height +0.0035971 weight).