Healthcare utilization and costs in chronic cough

Figures & data

Table 1. Demographics, anthropometrics, and clinical characteristics of participants with chronic cough.

	Participants with chronic cough (n = 100)
Age (years)	57.9 (14.6)
Gender (female)	69
BMI (kg/m^2)	27.9 (25.3–31.2)
Smoking status
Current	0
Ex	26
Never	74
Spirometry
FEV1 % predicted	92.8 (23.3)
FVC % predicted	104.6 (21.5)
Source of referral
Primary care	34
Secondary care	66
Duration of cough (years)*	3.0 (1.9–10.0)
Diagnoses
Refractory chronic cough	27
Unexplained chronic cough	57
Other	16
EQ-5Q-5L^†	0.846 (0.178)
GAD7
Probable generalized anxiety disorder (n%)	12
Some symptoms of anxiety (n%)	7
No anxiety symptom (n%)	81
PHQ9
Probable major depression (n%)	11
Some depressive symptoms (n%)	13
No depressive symptom (n%)	76
Cough severity VAS (mm)^‡	59.5 (30.0–79.0)
LCQ^‡
Physical	4.3 (1.2)
Psychological	3.9 (1.5)
Social	3.8 (1.6)
Total	11.9 (4.0)
24-hour cough monitoring (n = 57)^#
Total cough counts (coughs)	363.0 (2.6)
Total cough frequency (coughs/hr)	15.3 (2.5)

Data presented as mean (SD), median (IQR), or absolute number unless otherwise stated.

Abbreviations. BMI, body mass index; FEV₁, forced expiratory volume in 1 s; FVC, forced vital capacity; GAD7, Generalized Anxiety Disorder Assessment; PHQ9, Patient Health Questionnaire; VAS, visual analogue scale; LCQ, Leicester Cough Questionnaire. *n = 98, ^†n = 27, ^‡n = 96, ^§n = 57. ^#Geometric mean (SD).

Table 2. Cough-related healthcare utility and cost for 12 months prior to and 12 months following first specialist clinic consultation.

Items	Utilization by participants (n)	Utilization per participant	Cost per participant (GBP)
Cough clinic consultations	100	2.55 (1.08)	436.25 (123.81)
Imaging
Chest radiograph	99	1.33 (0.55)	41.23 (17.10)
CT chest	71	0.75 (0.52)	67.50 (46.78)
CT sinus	18	0.20 (0.45)	18.00 (40.45)
Subtotal imaging			126.73 (68.57)
Pulmonary function test
Spirometry	99	1.55 (0.59)	263.50 (100.72)
Body plethysmography	9	0.09 (0.29)	16.02 (51.20)
Diffusion capacity of CO	22	0.21 (0.41)	37.59 (73.78)
Reversibility	22	0.22 (0.42)	26.45 (51.31)
Methacholine challenge	1	0.01 (0.10)	1.97 (19.70)
Subtotal pulmonary function test			345.53 (155.30)
Other respiratory investigations
Skin prick test	20	0.20 (0.40)	34.80 (60.19)
Overnight pulse oximetry	20	0.20 (0.40)	38.80 (77.99)
Sputum culture	2	0.02 (0.14)	0.16 (1.13)
Bronchoscopy	14	0.14 (0.35)	39.06 (97.29)
Subtotal other respiratory investigations			112.82 (125.57)
Gastrointestinal investigations
Gastroscopy	11	0.11 (0.35)	38.72 (121.47)
Barium swallow	3	0.03 (0.17)	4.41 (25.20)
Video fluoroscopy	1	0.01 (0.10)	1.43 (14.30)
24-hour oesophageal manometry	23	0.24 (0.45)	137.76 (259.54)
Subtotal gastrointestinal investigations			182.32 (350.65)
Other investigations
Nasoendoscopy	13	0.13 (0.34)	16.25 (42.45)
Nerve conduction study	1	0.01 (0.10)	1.87 (18.70)
Ultrasound thyroid	1	0.01 (0.10)	0.54 (5.40)
Electrocardiogram	1	0.01 (0.10)	1.20 (12.00)
Subtotal other investigations			19.86 (55.13)
Other out-patient consultations
Ear, nose and throat	62	0.68 (0.58)	81.60 (70.08)
Gastroenterology	28	0.32 (0.55)	60.16 (103.08)
Immunology and allergy	4	0.04 (0.19)	8.84 (43.43)
Rheumatology	1	0.01 (0.10)	3.13 (31.30)
Subtotal other out-patient consultations			153.73 (134.36)
Medications
Antibiotics (unspecified)	15	0.17 (0.45)	0.19 (0.51)
Inhaled corticosteroid	61	0.75 (0.69)	9.04 (12.73)
Inhaled long-acting β-agonist	27	0.29 (0.50)	29.85 (86.99)
Prednisolone	77	0.83 (0.51)	2.22 (2.05)
Montelukast	3	0.03 (0.17)	0.70 (5.49)
Omeprazole	93	1.11 (0.49)	8.29 (14.43)
Nasal steroid	45	0.49 (0.58)	2.69 (3.44)
Gabapentin trial	43	0.49 (0.63)	2.54 (3.26)
Amitriptyline trial	8	0.29 (1.38)	0.34 (1.66)
Long-term gabapentin	25	0.27 (0.49)	9.11 (16.51)
Long-term amitriptyline	2	1.04 (7.31)	0.23 (1.63)
Subtotal medications			65.20 (97.28)
Other treatments
Physiotherapy/Speech (PSALTI)	61	0.63 (0.53)	153.72 (128.15)
Nissen fundoplication	2	0.02 (0.14)	51.76 (364.14)
Antral washout	1	0.01 (0.10)	14.93 (149.30)
Subtotal other treatments			220.41 (412.75)
Total costs over 2 years			1,662.85 (747.29)

Data presented as mean (SD) or absolute.

Abbreviations. CT, computer tomography; CO, carbon monoxide; PSALTI, physiotherapy and speech and language therapy intervention; GBP, British Pound Sterling.

Table 3. Multivariate analysis of potential predictors of cough-related healthcare costs following removal of co-linear variables.

Variables	Correlation coefficients	Bootstrap SE	p-values	95% CI
Age	1.049412	5.581534	.851	–9.890193 to 11.98902
Gender	143.4239	186.8128	.443	–222.7224 to 509.5702
Duration of cough	12.41278	9.750369	.203	–6.697588 to 31.52316
Diagnosis of unexplained chronic cough	280.3927	177.7009	.115	–67.89472 to 628.6802
LCQ total	–41.00865	19.63903	.037	–79.50044 to –2.516848
Anxiety case	–652.6497	167.3116	<.001	–980.5744 to –324.7251

Abbreviations. VAS, visual analogue scale; LCQ, Leicester Cough Questionnaire.

Bold values represent p < .05.