Table 2

Relationships among coughing, wheezing, and reflux

Type of relationship	No patients	Observed^2-150(SD)	Ratio^2-151OBS/EXP	z Value	p Value
Cough and reflux	53
Length of interaction: 0–2 min
Cough precedes reflux	28	6% (1%)	3.21	1.71	0.043
Reflux precedes cough	49	40% (3%)	2.48	5.08	0.000
Association of reflux and cough	49	46% (3%)	2.25	5.35	0.000
Length of interaction: 0–5 min
Cough precedes reflux	28	12% (2%)	2.70	2.18	0.014
Reflux precedes cough	50	50% (3%)	1.70	4.07	0.000
Association of reflux and cough	50	62% (4%)	1.61	4.17	0.000
Wheezes and reflux	19
Association of reflux and wheezes (for 2 min)	16	48% (7%)	2.30	2.71	0.003
Association of reflux and wheezes (for 5 min)	17	56% (7%)	1.62	1.66	0.050

↵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.