The Effect of Chronic Sputum Production on Respiratory Symptoms in Severe COPD

Figures & data

Table 1  Sputum Index

Variable	Score	Points
Sputum Quantity	None	0
	Scant	1
	<1/2 teaspoon	2
	≥1/2 teaspoon	3
	<1 tablespoon	4
	≥1 tablespoon	5
	≥1/4 cup	6
Sputum Color	None or white	0
	Yellow	1
	Green	2
	Brown	3
Sputum Consistency	None	0
	Watery	1
	Thin	2
	Thick	3

Sputum Index. These points were assigned on a daily basis, and the average sputum score across the observation period determined to which group each patient was assigned. Low = 0–3; Medium = 3–7; High = >7.

Table 2  Symptom severity score

Category	Scoring
Major Symptoms
Breathlessness	+1.0 if ≥3 points above baseline
Sputum Quantity	+0.5 if change to greater amount from baseline
Sputum Color	+0.5 if change in color from baseline
Sputum Consistency	+0.5 if change from baseline and change is from none, watery, or thin to thick
Peak Flow	+1.0 if ≤80% of baseline
Temp over 100°F	+0.5 if answer is “Yes”
Minor Symptoms
Cough	+0.5 if ≥2 minor symptoms
Wheeze	+0.5 if ≥2 minor symptoms
Sore Throat	+0.5 if ≥2 minor symptoms
Nasal Congestion	+0.5 if ≥2 minor symptoms
Symptom Severity	Total Score
None	0–0.5
Mild	1.0–1.5
Moderate	2.0–2.5
Severe	≥3.0

Patients were assigned points on a daily basis, and symptom severity was determined based on the composite score (© G.J. Criner, 2004, US copyright # TX7-170-236) and categorized into mild, moderate, and severe symptoms.

Table 3  Patient characteristics

	Low (n = 22)	Medium (n = 14)	High (n = 14)	P
Age (yr)	62 ± 6	65 ± 8	63 ± 7	NS
Smoking (pk-yr)	55 ± 28	49 ± 20	50 ± 21	NS
M/F (no.)	7/15	7/7	5/9	NS
Race C/AA (no.)	15/7	9/5	11/3
Lung Function
FEV1 (%)	26 ± 7	31 ± 9	26±7	NS
%Ch FEV1 after SABA	7 ± 11	9 ± 14	12 ± 13	NS
FVC (%)	68 ± 15	67 ± 17	69 ± 12	NS
%Ch FVC after SABA	16 ± 13	15 ± 16	16 ± 12	NS
TLC (%)	112 ± 18	117 ± 19	113 ± 12	NS
RV (%)	184 ± 49	196 ± 56	187 ± 43	NS
DLCO/VA (%)	50 ± 18	60 ± 18	50 ± 9	NS
6MWD (m)	244 ± 76	242 ± 85	272 ± 94	NS
PaO2, RA (mm Hg)	65 ± 12	69 ± 14	63 ± 7	NS
PaCO2, RA (mm Hg)	44 ± 8	45 ± 8	43 ± 6	NS
BMI (kg/m^2)	29 ± 6	30 ± 8	30 ± 6	NS
MMRC	2.9 ± 1.0	2.9 ± 0.8	2.5 ± 1.0	NS
BODE score	6.3 ± 1.5	6.3 ± 1.4	5.7 ± 1.7	NS
Respiratory Meds
SABA (no. (%))	22 (100)	14 (100)	14 (100)	NS
LABA (no. (%))	20 (91)	12 (86)	10 (71)	NS
LAAC (no. (%))	17 (74)	12 (86)	7 (50)	NS
ICS (no. (%))	9 (39)	7 (50)	7 (50)	NS
OCS (no. (%))	17 (74)	7 (50)	6 (43)	NS
Oxygen (no. (%))	17 (74)	8 (57)	11 (76)	NS

Expressed as mean ± SD. C = Caucasian, AA = African American, 6MWD = 6 minute walk distance, RA = room air, SABA = short-acting bronchodilator, LABA = long-acting beta-agonist, LAAC = long-acting anticholinergic, ICS = inhaled corticosteroids, OCS = oral corticosteroids (use within 1 year prior to enrollment), %Ch FEV₁ after SABA = percent difference in FEV₁ pre- and post-bronchodilator, %Ch FVC after SABA = percent difference in FVC pre- and post-bronchodilator.

Table 4  Results

	Low (n = 22)	Medium (n = 14)	High (n = 14)	P
Avg. Number of Observation Days per Patient	277 ± 152	292 ± 191	332 ± 156	NS
Sputum Quantity	0.64 ± 0.57	3.70 ± 0.76	4.67 ± 0.48	<0.0001^†
Sputum Color	0.04 ± 0.05	0.20 ± 0.21	0.64 ± 0.57	<0.001*
Sputum Consistency	0.30 ± 0.24	1.71 ± 0.33	2.6 ± 0.41	<0.0001^†
Severe Symptom Days/Total Observ Days (%)	379/6089 (6.2)	1609/4091 (39.3)	2624/4317 (60.8)	<0.0001^†
Severe Symptom Days/Total Observ Days, sputum score excluded (%)	12/6089 (0.2)	13/4091 (0.3)	96/4317 (2.2)	<0.0001^†
% Severe Symptom Days/Patient	6.8 ± 9.5	38.4 ± 38.5	71.0 ± 33.3	<0.0001^†
Mod+Sev Symptom Days/Total Observ Days (%)	2349/6089 (38.6)	3382/4091 (82.7)	4303/4317 (99.7)	<0.0001^†
Mod+Sev Symptom Days/Total Observ Days, sputum score excluded (%)	2086/6089 (34.3)	1785/4091 (43.6)	2222/4317 (51.5)	<0.0001^†
% Mod+Sev Symptom Days/Patient	41.9 ± 40.0	83.8 ± 22.0	99.7 ± 0.6	<0.0001^†
%Emphysema at -950HU**	26 ± 10 (n = 8)	18 ± 10 (n = 6)	14 ± 12 (n = 9)	0.10
Daily PF/PF predicted, avg.	0.56 ± 0.24	0.53 ± 0.19	0.42 ± 0.12	<0.0001*

Expressed as mean ± SD. PF = peak flow, PF predicted based on NHANES III data. HU = Hounsfield units.*p < 0.05 for differences of High group compared to Medium and Low groups; ^†p < 0.0001 for differences between Low, Medium, and High groups. **Numbers in each group lower for emphysema quantitation only.

Figure 1  Percent of total patient observation days meeting criteria for severe symptoms in each tertile. p < 0.0001 for differences between Low, Medium, and High.

Figure 2  Average daily sputum index by individual patient, shown in Panel A. Average individual components of the sputum index (quantity, color, and consistency) shown in Panels B, C, and D. Patients ranked by average daily sputum index. x = Low, + = Medium, Δ = High.

Figure 3  Average daily Sputum Index (A) and quantity (B) compared to percent emphysema. %Emph = percent lung attenuation at −950 Hounsfield units. n = 23.