Impact and factors associated with nighttime and early morning symptoms among patients with chronic obstructive pulmonary disease

Figures & data

Figure 1 Flow chart of survey respondents.

Abbreviations: EM, early morning; HIRD, HealthCore Integrated Research Database; NT, nighttime.

Table 1 Demographic and clinical characteristics of survey respondents

	Total Respondents N=752	Both NT and EM symptoms n=318	Either NT or EM symptoms n=246	Neither NT nor EM symptoms n=188	P-valuea
Age (years), mean (SD)	60.2 (8.0)	58.6 (7.8)	61.0 (8.1)	62.0 (7.8)	<0.01
Female, %	60.5	57.6	63.8	61.2	0.31
White/Caucasian, %	91.6	92.7	91.0	90.4	0.61
Education status, %					0.05
High school or less	41.9	46.8	37.1	39.9
Some college and above	58.1	53.2	62.9	60.1
Household income, % (US$)					0.01
Less than $25,000	13.3	17.3	8.8	12.1
$25,000 to $74,999	60.1	61.0	61.0	57.2
$75,000 and over	26.7	21.7	30.3	30.6
Employment status, %					0.12
Full-time	47.5	46.5	48.0	48.7
Part-time	10.7	7.9	11.4	14.4
Not working	41.8	45.6	40.7	36.9
Age at COPD diagnosis (years), mean ± SD	53.5±9.2	51.5±9.1	54.7±8.7	55.5±9.4	<0.01
COPD duration (years),b mean ± SD	6.5±6.3	7.1±6.9	6.0±5.5	6.2±6.0	0.11
Smoking status, %					<0.01
Current smoker	28.9	38.1	24.0	19.9
Former smoker	58.1	49.1	64.2	65.6
Never smoked	12.9	12.9	11.8	14.5
Overweight/obese,c %	69.7	72.4	66.7	69.2	0.33
Oxygen use in the past week, %	15.8	20.4	16.3	7.5	<0.01
Sleep medication use in the past week, %	33.4	39.0	32.9	24.5	<0.01
Oral steroid use in the past week, %	29.9	32.1	25.6	31.9	0.20
COPD exacerbation in the past year, %	21.5	29.3	18.7	12.2	<0.01
CAT score categories, %					<0.01
Low (<10)	26.4	6.6	27.9	57.8
Medium (10–20)	43.1	39.2	54.1	35.3
High (21–30)	24.5	39.9	18.0	7.0
Very high (31–40)	6.0	14.2	0.0	0.0
mMRC dyspnea score categories,d %					<0.01
0	28.3	13.9	32.4	48.1
1–4	71.7	86.1	67.6	51.9
MMAS-8 adherence level,e %					<0.01
Medication nonusers	14.5	10.1	12.6	24.5
Low adherence (0–5)	23.3	30.9	19.9	14.9
Moderate adherence (6–7)	31.2	35.3	31.3	23.9
High adherence (8)	31.0	23.7	36.2	36.7

Notes:

a Analysis of variance was used for continuous variables whereas chi-square/Fisher’s exact test was used for categorical variables.

b Duration of COPD was calculated using age at the survey minus age at COPD diagnosis.

c Overweight/obese was defined as body mass index ≥25 kg/m², which was calculated as weight in pounds divided by square of height in inches multiplied by 703.

d Patients were considered as having dyspnea symptoms if mMRC dyspnea scale responses =1–4 and were considered as being without dyspnea symptoms if mMRC scale response =0.

e Patients were categorized into four levels: 1) patients who did not take any COPD-related medications; 2) patients who took COPD-related medications and had a MMAS-8 score =0–5 (low adherence); 3) patients who took COPD-related medications and had a MMAS score =6–7 (moderate adherence); and 4) patients who took COPD-related medications and had a MMAS score =8 (high adherence).

Abbreviations: CAT, COPD Assessment Test; COPD, chronic obstructive pulmonary disease; EM, early morning; MMAS-8, Morisky Medication Adherence Scale; mMRC, modified Medical Research Council; NT, nighttime; SD, standard deviation.

Table 2 Type, severity, and impact of NT symptoms

	Respondents with NT symptoms	N=376
Types of NT symptoms over past week
Short of breath or breathless, n, %	231	61.4%
Nights with shortness of breath or breathlessness, mean ± SD	4.5	±2.0
Coughing, n, %	274	72.9%
Nights with coughing, mean ± SD	4.9	±2.1
Bringing up phlegm or mucus, n, %	229	60.9%
Nights with bringing up phlegm or mucus, mean ± SD	4.8	±2.1
Tightness in chest, n, %	164	43.6%
Nights with tightness in chest, mean ± SD	4.2	±2.2
Chest congestion, n, %	183	48.7%
Nights with chest congestion, mean ± SD	4.9	±2.0
Wheezing, n, %	260	69.2%
Nights with wheezing, mean ± SD	5.0	±2.1
Severity of NT symptoms over past week, n, %
Did not experience any symptoms	9	2.4%
Mild	179	47.6%
Moderate	160	42.6%
Severe	23	6.1%
Very severe	5	1.3%
Impact of NT symptoms over past week
Difficult to fall asleep, n, %	190	25.3%
Nights on which it felt difficult to fall asleep, mean ± SD	3.8	±2.1
Sleep disturbed, n, %
Not at all	81	22.1%
Slightly	122	33.2%
Moderately	130	35.4%
Severely	21	5.7%
Extremely	12	3.3%
Refused to answer	1	0.3%
Woke up at least once, n, %	259	34.4%
Nights woke up, mean ± SD	3.8	±2.1
Felt rested in morning, n, %	230	30.6%
Mornings felt rested, mean ± SD	4.0	±2.0
Anxious, n, %
Not at all anxious	150	40.9%
Slightly anxious	105	28.6%
Moderately anxious	67	18.3%
Considerably anxious	29	7.9%
Extremely anxious	16	4.4%
Used rescue medications, n, %	190	25.3%

Abbreviations: NT, nighttime; SD, standard deviation.

Table 3 Type, severity, and impact of EM symptoms

	Respondents with EM symptoms	N=506
Types of EM symptoms over past week
Short of breath or breathless, n, %	374	73.4%
Nights with shortness of breath or breathlessness, mean ± SD	5.0	±2.1
Coughing, n, %	377	74.5%
Nights with coughing, mean ± SD	5.6	±1.9
Bringing up phlegm or mucus, n, %	352	69.6%
Nights with bringing up phlegm or mucus, mean ± SD	5.4	±2.0
Tightness in chest, n, %	207	40.9%
Nights with tightness in chest, mean ± SD	4.3	±2.2
Chest congestion, n, %	233	46.1%
Nights with chest congestion, mean ± SD	4.9	±2.1
Wheezing, n, %	300	59.3%
Nights with wheezing, mean ± SD	5.0	±2.2
Severity of EM symptoms over past week, n, %
Mild	222	43.9%
Moderate	234	46.3%
Severe	45	8.9%
Very severe	4	0.8%
Impact of EM symptoms over past week
Activity limited, n, %
Not at all	200	39.6%
Slightly	113	22.4%
Moderately	96	19.0%
Severely	62	12.3%
Extremely	34	6.7%
Trouble concentrating, n, %	209	27.8%
Mornings trouble concentrating, mean ± SD	4.3	±2.0
Anxious, n, %
Not at all	229	45.4%
Slightly	145	28.7%
Moderately	74	14.7%
Considerably	41	8.1%
Extremely	14	2.8%
Refused to answer	2	0.4%
Used rescue medications, n, %	326	43.4%

Abbreviations: EM, early morning; SD, standard deviation.

Figure 2 Factors associated with NT and/or EM symptoms in patients with COPD.

Notes: ^aResults were from a single multinomial model with neither NT nor EM symptoms as the reference group. ^bRepresented by medium or high CAT scores. Patients were categorized into two levels: medium/high level if CAT score ≥10, and low level if CAT score <10 (reference group). ^cPatients were considered as having dyspnea symptoms if mMRC scale was within 1–4, and without dyspnea symptoms if mMRC =0 (reference group). ^dPatients were categorized into four levels: 1) patients who did not take any COPD-related medications; 2) patients who took COPD-related medications and had a MMAS score of 0–5 (low adherence); 3) patients who took COPD-related medications and had a MMAS score within 6–8 (moderate adherence); and 4) patients who took COPD-related medications and had a MMAS score =8 (high adherence as reference group).
Abbreviations: CAT, COPD Assessment Test; COPD, chronic obstructive pulmonary disease; EM, early morning; MMAS, Morisky Medication Adherence Scale; mMRC, modified Medical Research Council; NT, nighttime.