. 2016 Mar 15;193(6):634–641. doi: 10.1164/rccm.201506-1169OC

Table 2.

Baseline Characteristics of VIDA Randomized Participants with Colds: Continuous Variables

	Vitamin D (N = 110)			Placebo (N = 93)			P Value^*
Characteristic	N	Mean	SD	N	Mean	SD	P Value^*
Age, yr	110	39.6	12.1	93	39.2	12.8	0.85^†
Duration of asthma since doctor first diagnosed, yr	110	24.9	13.2	93	25.0	13.4	0.94^†
BMI, kg/m²	110	32.42	8.39	93	31.47	9.85	0.46^†
Number of positive skin tests^‡	106	4.00	(2.00–6.00)	88	3.50	(2.00–6.00)	0.41^§
Peak flow, 2-wk average, L/min
a.m.	110	401.5	97.3	93	393.1	106.6	0.56^†
p.m.	110	406.5	102.6	93	395.4	106.7	0.45^†
Symptoms, 2-wk average over 5 types^║
a.m.	110	0.36	0.27	93	0.40	0.36	0.34^†
p.m.	110	0.38	0.29	93	0.46	0.41	0.13^†
Prebronchodilator FEV₁, L	110	2.62	0.76	93	2.61	0.83	0.98^†
Prebronchodilator FEV₁% predicted	110	80.9	14.0	93	81.1	14.2	0.92^†
Prebronchodilator FEV₁/FVC ratio	110	0.73	0.09	93	0.71	0.09	0.24^†
Improvement in prebronchodilator FEV₁ over OCS response period, %	92	−0.93	7.42	78	−0.17	8.04	0.52^†
Imputed PC₂₀^¶, mg/ml	106	2.14	1.58	88	2.09	1.61	0.92^**
Sputum eosinophils^‡, %	90	0.25	(0.00–1.30)	80	0.25	(0.00–1.30)	0.81^§
Maximum post-albuterol FEV₁% predicted	110	91.61	14.30	92	93.16	13.98	0.44^†
Maximum reversibility, % change	110	16.03	11.91	92	18.41	11.80	0.16^†
Vitamin D, ng/ml	110	18.05	(13.70–23.70)	93	19.70	(14.80–24.80)	0.29^§
Melanin level
Upper inner arm	108	63.6	(51.4–68.1)	91	65.3	(61.5–67.5)	0.16^§
Outer forearm	107	56.7	(45.4–60.9)	92	58.3	(52.7–62.4)	0.04^§
Exposed forehead	108	56.0	(44.8–60.9)	92	58.2	(52.7–62.3)	0.02^§
Abdomen	108	62.0	(45.8–68.0)	92	64.5	(57.6–68.8)	0.08^§
ASUI score	110	0.84	0.10	92	0.82	0.12	0.18^†
ACT score^††	110	20.0	(17.0–22.0)	93	20.0	(17.0–22.0)	0.80^§
Asthma control days
Proportion of controlled days, 2-wk average	110	0.20	0.27	93	0.17	0.24	0.39^†
Number of controlled days, 2-wk sum	110	2.81	3.75	93	2.38	3.39	0.39^†
ABP score	110	19.0	(13.0–26.0)	93	18.0	(13.0–28.0)	0.66^§

Definition of abbreviations: ABP = Asthma Bother Profile; ACT = Asthma Control Test; ASUI = Asthma Symptom Utility Index; BMI = body mass index; OCS = oral corticosteroid response to prednisone 40 mg by mouth once daily for 5–7 days; PC₂₀ = provocative concentration of methacholine that decreased FEV₁ by 20%, with maximum reversibility after up to eight puffs (360 μg) of inhaled levalbuterol; VIDA = Vitamin D Add-on Therapy Enhances Corticosteroid Responsiveness trial.

Placebo versus vitamin D.

^{^†}

t test for differences between specified groups.

^{^‡}

Median (interquartile range) is reported.

^{^§}

Wilcoxon rank-sum test for differences between specified groups.

^{^║}

Symptoms scale: 0 = absent, 1 = mild, 2 = moderate, 3 = severe. Symptom types: shortness of breath, chest tightness, wheezing, cough, and phlegm/mucus.

^{^¶}

Geometric mean (coefficient of variation) reported.

^**

t test for differences between specified groups on logarithmic scale.

^{^††}

Individual ACT questions are scaled 1–5, with higher values representing better asthma control. ACT score is sum of answers to questions 1–5.