Table 2

Relationships among coughing, wheezing, and reflux

Type of relationship No
Observed2-150(SD) Ratio2-151OBS/EXP z Value p Value
Cough and reflux53
 Length of interaction: 0–2 min
  Cough precedes reflux28 6% (1%)3.211.710.043
  Reflux precedes cough4940% (3%)2.485.080.000
  Association of reflux and cough4946% (3%)2.255.350.000
 Length of interaction: 0–5 min
  Cough precedes reflux2812% (2%)2.702.180.014
  Reflux precedes cough5050% (3%)1.704.070.000
  Association of reflux and cough5062% (4%)1.614.170.000
Wheezes and reflux19
 Association of reflux and wheezes (for 2 min)1648% (7%)2.302.710.003
 Association of reflux and wheezes (for 5 min)1756% (7%)1.621.660.050
  • 2-150 The total number of coughs or wheezes corresponds to 100%, mean percentage calculated as mean of individual patient means with SDs.

  • 2-151 The ratio represents the fraction of observed over expected coincidences of coughs and reflux or wheezes and reflux.