. 2015 Mar 6;10:475–487. doi: 10.2147/COPD.S75776

Table 4.

Correlation^a of NiSCI scores with SGRQ, E-RS total, and FEV₁^b at baseline week

	Six-item symptom severity score^c	Overall symptoms severity score^d	Number of nighttime awakenings score	Rescue medication score
SGRQ total score	0.58^***	0.57^***	0.45^***	0.35^***
SGRQ symptoms score	0.66^***	0.60^***	0.45^***	0.39^***
SGRQ impacts score	0.55^***	0.53^***	0.45^***	0.35^***
E-RS total score	0.76^***	0.73^***	0.50^***	0.36^***
FEV₁ (trough)^b	−0.01	−0.04	0.01	−0.06

Notes:

Spearman rank order correlation coefficients

^***

P<0.0001.

Morning predose value.

Average score of six symptom severity items (cough, wheezing, shortness of breath, tightness in your chest, chest congestion, and difficulty bringing up phlegm).

Single item on overall nighttime symptoms severity.

Abbreviations: NiSCI, Nighttime Symptoms of COPD Instrument; SGRQ, St George’s Respiratory Questionnaire; E-RS, Exacerbations of Chronic Obstructive Pulmonary Disease Tool-Respiratory Symptoms; FEV₁, forced expiratory volume in 1 second.