Associations with Post-Consultation Health-Status in Primary Care Managed Acute Exacerbation of COPD

Figures & data

Table 1 Explanatory Variables Studied

Domain	Variables
Sociodemographic variables	Age, sex, and Body Mass Index (BMI).
Clinical history	Heart failure, coronary heart disease, diabetes (either type I or II), chronic kidney disease (CKD 3 or more), hypertension, smoking status (categorised as never smoked/ever smoked for modelling purposes), percent predicted FEV1 (a marker of COPD severity), and whether the patient had been prescribed oral antibiotics for any reason in the 12 months prior to their exacerbation.
Presenting features of the acute exacerbation	Season during which the consultation occurred, number of days with symptoms prior to consulting, presence of increased breathlessness, increased sputum volume, increased sputum purulence, sputum colour (estimated by the treating clinician if the patient was able to produce sputum during the consultation, or graded by the patient if not, from 1 (least purulent) to 5 (most purulent) according to the BronkoTest^®), presence of chest sounds (crackles, wheeze, diminished vesicular breathing), whether the patient was tachypnoeic, body temperature, pulse rate, and oxygen saturation.

Table 2 Characteristics of Participants at the Index Consultation

Variable		Frequency	%
Participant sex (n=649)	Male	335	51.6
	Female	314	48.4
Body Mass Index category (n=603)	Underweight	22	3.6
	Healthy weight	175	29.0
	Overweight	193	32.0
	Obese	213	35.3
Heart failure (n=649)		31	4.8
Chronic heart disease (n=649)		114	17.6
Diabetes (n=649)		104	16.0
Chronic kidney disease (n=649)		59	9.1
Hypertension (n=649)		267	41.1
Smoking status (n=560)	Never smoked	42	7.5
	Ever smoked	518	92.5
Patient has been prescribed oral antibiotics in the past 12 months for any reason (n=606)		403	66.5
Season of presentation (n=649)	Winter	323	49.8
	Spring	110	16.9
	Summer	48	7.4
	Autumn	168	25.9
Number of days with exacerbation prior to consulting (n=649)	1 to 6 days	366	56.4
	7 to 13 days	166	25.6
	14+ days	117	18.0
Increased breathlessness (n=649)		583	89.8
Increase sputum volume (n=649)		464	71.5
Increased sputum purulence (n=649)		389	59.9
Sputum colour (n=577)	Sputum colour 1	135	23.4
	Sputum colour 2	126	21.8
	Sputum colour 3	136	23.6
	Sputum colour 4	140	24.3
	Sputum colour 5	40	6.9
Crackles (n=649)		320	49.3
Wheeze (n=649)		338	52.1
Diminished vesicular breathing (n=647)		153	23.6
Patient is tachypnoeic (n=589)		88	14.9
Oxygen saturation (n=646)	Normal or moderately decreased (> 92%)	577	89.3
	Low (up to 92%)	69	10.7
Variable		Mean	SD
Age (n=649)		68.1	9.42
Percent predicted FEV1 (n=559)		59.8	20.04
Body Temperature (n=648)		36.7	0.49
Pulse rate (n=648)		81.6	12.74

Figure 1 Predicted mean CCQ total scores over time (note full CCQ total score ranges from 0 to 6)*. *Dashed line denotes a difference of 0.4 from the estimated mean CCQ total score at the index consultation.

Table 3 Individual Associations Between Sociodemographic, Past Medical History, and Clinical Variables and Exacerbation Course in Patients with AECOPD in Primary Care*

Domain	Variable		AMD	Lower 95% CI	Upper 95% CI	p-value
Sociodemographics	Age (per decade increase)		0.02	−0.06	0.09	0.688
	Participant sex	Male	Reference category
		Female	−0.14	−0.28	0.00	0.054
	Body Mass Index category	Underweight	0.36	−0.02	0.74	0.064
		Healthy weight	Reference category
		Overweight	0.09	−0.09	0.27	0.339
		Obese	0.25	0.07	0.43	0.006
Past medical history	Heart failure		0.22	−0.11	0.55	0.194
	Chronic heart disease		0.13	−0.06	0.31	0.176
	Diabetes		0.26	0.08	0.45	0.005
	Chronic kidney disease		0.21	−0.02	0.45	0.077
	Hypertension		0.11	−0.04	0.25	0.142
	Smoking status	Never smoked	Reference category
		Ever smoked	0.13	−0.16	0.42	0.371
	Patient has been prescribed oral antibiotics in the past 12 months for any reason		0.26	0.11	0.41	0.001
	Percent predicted FEV1 (per 10-point increase)		−0.03	−0.06	0.00	0.160
Initial presenting features	Season of presentation	Winter	Reference category
		Spring	0.00	−0.20	0.21	0.980
		Summer	−0.02	−0.31	0.26	0.873
		Autumn	−0.10	−0.28	0.08	0.261
	Number of days with exacerbation prior to consulting	1 to 6 days	Reference category
		7 to 13 days	−0.01	−0.18	0.16	0.906
		14+ days	0.08	−0.11	0.27	0.423
	Increased breathlessness		0.07	−0.17	0.32	0.558
	Increase sputum volume		−0.01	−0.17	0.14	0.869
	Increased sputum purulence		0.11	−0.04	0.26	0.134
Estimated sputum colour	Sputum colour	Sputum colour 1	Reference category
		Sputum colour 2	−0.00	−0.21	0.21	0.977
		Sputum colour 3	0.14	−0.08	0.35	0.212
		Sputum colour 4	0.06	−0.14	0.27	0.546
		Sputum colour 5	0.16	−0.15	0.48	0.313
Chest sounds	Crackles		−0.03	−0.19	0.12	0.662
	Wheeze		−0.08	−0.24	0.07	0.302
	Diminished vesicular breathing		−0.10	−0.27	0.08	0.286
Other clinical examinations	Patient is tachypnoeic		0.11	−0.11	0.34	0.322
	Body Temperature (per degree increase)		−0.13	−0.27	0.01	0.078
	Pulse rate (per one bpm increase)		0.00	−0.00	0.01	0.083
	Oxygen saturation	Normal or moderately decreased (> 92%)	Reference category
		Low (up to 92%)	0.14	−0.10	0.37	0.260

Notes: *All models correct for the clustered nature of repeated observations within individuals within practices (1947 observations within 649 individuals within 86 practices). Models adjust for time point (one-, two-, and four-weeks post-consultation), CCQ total score at the index consultation, trial arm (managed using a CRP point-of-care test in addition to usual care or usual care alone), antibiotic prescribing, and oral corticosteroid prescribing at the index consultation.

Abbreviation: AMD, adjusted mean difference.

Table 4 Marginal R² Values Across Multivariable Models

Block	Description	Marginal R^2	Absolute Difference	Relative Difference (%)
0	No explanatory variables*	0.594	N/A	N/A
1	Sociodemographics	0.621	0.027	4.5
2	Past medical history	0.661	0.04	6.4
3	Initial presenting features	0.668	0.007	1.1
4	Estimated sputum colour	0.671	0.003	0.4
5	Presence of abnormal chest sounds	0.693	0.022	3.3
6	Other clinical examinations	0.718	0.025	3.6

Notes: *Model included time point, CCQ total score at the index consultation, trial arm, antibiotic prescribing, and oral corticosteroid prescribing at the index consultation.