Skip to main content

Table 3 Pearson’s correlation coefficients between spirometric variables and measured covariates

From: Validation of the global lung initiative 2012 multi-ethnic spirometric reference equations in healthy urban Zimbabwean 7–13 year-old school children: a cross-sectional observational study

Spirometry variables

(z-score)

Covariate

HAZ

WAZ

BMI Z

Age (years)

FVC

− 0.113(− 0.185–0.040)

0.022(− 0.052 0.095)

0.132(0.059 0.204)

−0.119(− 0.190–0.045)

FEV1

− 0.124(− 0.195–0.051)

−0.056(− 0.129 0.017)

0.025(− 0.049 0.098)

−0.007(− 0.066 0.081)

FEV 1/FVC

− 0.018(− 0.091 0.056)

−0.122(− 0.193–0.049)

−0.166(− 0.237–0.094)

0.181(0.109 0.251)

MMEF

−0.053(− 0.126 0.020)

−0.068(− 0.141 0.006)

−0.057(− 0.130 0.016)

0.105(0.031 0.176)

  1. HAZ Height for Age z-score, WAZ Weight for Age z-score, BMI Z Body Mass Index for age z-score calculated using the 1990 British anthropometric reference values
  2. FVC Forced vital capacity, FEV1 Forced expiratory volume in one second, FEV1/FVC Ratio of FEV1 to FVC, MMEF Maximal mid-expiratory flow
  3. NOTE: All values are correlations (95% confidence interval limits)