Table 2

Comparison of mean height z-scores of the John Hunter Hospital cystic fibrosis clinic population with the normal population (mean z-score, zero), within five year age groupings in 1993 and 1997

Age group (years)	n	Height z-score (mean)	95% CI	p Value
Height z-score 1997
0 to ⩽ 5	14	−0.00	−0.52 to 0.52	1.0
> 5 to ⩽10	14	−0.41	−0.93 to 0.12	0.13
> 10 to ⩽ 15	19	−0.05	−0.50 to 0.40	0.84
> 15 to ⩽ 20	19	−0.98	−1.43 to −0.54	< 0.001
> 20	18	−0.89	−1.35 to −0.43	< 0.001
Height z-score 1993
0 to ⩽ 5	18	−0.32	−0.78 to 0.14	0.17
> 5 to ⩽ 10	17	0.28	−0.19 to 0.76	0.24
> 10 to ⩽ 15	20	−0.88	−1.32 to −0.44	< 0.001
> 15 to ⩽ 20	12	−0.92	−1.49 to −0.36	< 0.001
> 20	8	−1.05	−1.74 to −0.36	0.003

Assumed ς = 1.