Short- and Long-Term Impact of Prior Chronic Obstructive Pulmonary Disease Exacerbations on Healthcare Resource Utilization and Related Costs: An Observational Study (SHERLOCK)

Figures & data

Table 1. Adjusted rate ratios versus Group A (no exacerbations) for all-cause and COPD-related HCRU by exacerbation history^a at 12, 24, and 36 months of follow-up.

Adjusted^b RR (95% CI)	Group B (n = 5151)		Group C (n = 250)		Groups B + C (n = 5401)		Group D (n = 9273)
	All-cause	COPD-related	All-cause	COPD-related	All-cause	COPD-related	All-cause	COPD-related
12 months of follow-up
PC/GP visits	1.02 (1.00, 1.05)	1.03 (1.01, 1.06)	1.21 (1.11, 1.31)	1.14 (1.05, 1.24)	1.03 (1.01, 1.06)	1.04 (1.02, 1.06)	1.20 (1.18, 1.22)	1.24 (1.22, 1.27)
Outpatient visits^c	1.05 (0.99, 1.12)	1.04 (0.87, 1.23)	1.31 (1.07, 1.61)	1.14 (0.75, 1.74)	1.06 (1.00, 1.13)	1.04 (0.88, 1.23)	1.27 (1.21, 1.34)	1.23 (1.07, 1.41)
Total hospitalizations	0.98 (0.88, 1.10)	0.82 (0.60, 1.11)	1.29 (0.95, 1.76)	1.10 (0.59, 2.03)	0.99 (0.89, 1.11)	0.83 (0.61, 1.12)	1.41 (1.28, 1.54)	1.47 (1.15, 1.87)
Total HCRU components^d	1.04 (1.01, 1.06)	1.04 (1.02, 1.06)	1.28 (1.18, 1.39)	1.18 (1.09, 1.29)	1.05 (1.02, 1.07)	1.05 (1.02, 1.07)	1.26 (1.23, 1.28)	1.29 (1.26, 1.31)
24 months of follow-up
PC/GP visits	1.02 (1.00, 1.04)	1.04 (1.01, 1.06)	1.17 (1.08, 1.27)	1.12 (1.03, 1.21)	1.03 (1.01, 1.05)	1.04 (1.02, 1.06)	1.20 (1.17, 1.22)	1.24 (1.22, 1.27)
Outpatient visits^c	1.05 (0.99, 1.10)	1.01 (0.88, 1.14)	1.18 (0.99, 1.40)	1.08 (0.78, 1.51)	1.05 (1.00, 1.11)	1.01 (0.89, 1.15)	1.27 (1.22, 1.33)	1.31 (1.19, 1.45)
Total hospitalizations	0.98 (0.90, 1.07)	0.97 (0.79, 1.20)	1.54 (1.21, 1.98)	1.74 (1.09, 2.77)	1.00 (0.92, 1.09)	1.00 (0.81, 1.23)	1.44 (1.34, 1.54)	1.74 (1.48, 2.06)
Total HCRU components^d	1.03 (1.01, 1.05)	1.04 (1.02, 1.06)	1.24 (1.14, 1.34)	1.16 (1.08, 1.26)	1.04 (1.02, 1.06)	1.04 (1.02, 1.07)	1.25 (1.23, 1.27)	1.28 (1.26, 1.31)
36 months of follow-up
PC/GP visits	1.02 (1.00, 1.05)	1.04 (1.02, 1.06)	1.16 (1.07, 1.26)	1.11 (1.03, 1.20)	1.03 (1.01, 1.05)	1.04 (1.02, 1.06)	1.19 (1.17, 1.22)	1.24 (1.22, 1.26)
Outpatient visits^c	1.04 (0.99, 1.09)	1.01 (0.90, 1.13)	1.13 (0.96, 1.33)	1.23 (0.90, 1.67)	1.05 (1.00, 1.10)	1.02 (0.91, 1.14)	1.28 (1.23, 1.33)	1.37 (1.25, 1.51)
Total hospitalizations	1.02 (0.95, 1.10)	1.07 (0.91, 1.26)	1.82 (1.47, 2.27)	1.67 (1.16, 2.40)	1.05 (0.98, 1.12)	1.09 (0.93, 1.28)	1.51 (1.42, 1.60)	1.85 (1.62, 2.11)
Total HCRU components^d	1.03 (1.01, 1.05)	1.04 (1.02, 1.07)	1.23 (1.14, 1.33)	1.17 (1.08, 1.26)	1.04 (1.02, 1.06)	1.05 (1.03, 1.07)	1.24 (1.22, 1.26)	1.28 (1.26, 1.31)

Notes: CI, confidence interval; COPD, chronic obstructive pulmonary disease; HCRU, healthcare resource utilization; MRC, Medical Research Council; n, number of patients; PC/GP, primary care/general practitioner; RR, rate ratio.

a Exacerbation history groups: Group B, 1 moderate exacerbation only; Group C, 1 severe exacerbation only; Group D, ≥2 prior moderate and/or severe exacerbations.

b Adjustment for the following baseline sociodemographic and clinical characteristics: sex, age, smoking status, cardiovascular disease, cerebrovascular disease, depression, and MRC dyspnoea score.

c COPD-related outpatient visits are defined as visits to a respiratory medicine clinic.

d Total HCRU components (sum of PC, outpatient, emergency room, intensive care visits, and general ward stays).

Table 2. Relative all-cause and COPD-related costs (£) versus Group A by exacerbation history^a group at 12, 24 and 36 months of follow-up.

	Group B (n = 5151)		Group C (n = 250)		Groups B + C (n = 5401)		Group D (n = 9273)
	All-cause	COPD-related	All-cause	COPD-related	All-cause	COPD-related	All-cause	COPD-related
Adjusted^bmodel: relative cost^c (95% CI)
12 months of follow-up	1.03 (0.94, 1.12)	1.06 (0.99, 1.13)	1.47 (1.07, 2.01)	1.54 (1.20, 1.97)	1.04 (0.96, 1.14)	1.08 (1.01, 1.15)	1.47 (1.36, 1.58)	1.63 (1.54, 1.73)
24 months of follow-up	1.03 (0.96, 1.11)	1.03 (0.97, 1.09)	1.47 (1.12, 1.91)	1.61 (1.28, 2.03)	1.05 (0.98, 1.13)	1.05 (0.99, 1.12)	1.39 (1.31, 1.48)	1.56 (1.48, 1.65)
36 months of follow-up	1.02 (0.96, 1.08)	1.04 (0.98, 1.11)	1.53 (1.20, 1.93)	1.67 (1.33, 2.09)	1.04 (0.97, 1.10)	1.07 (1.01, 1.13)	1.37 (1.29, 1.45)	1.60 (1.51, 1.68)

CI, confidence interval; COPD, chronic obstructive pulmonary disease; MRC, Medical Research Council; n, number of patients.

a Exacerbation history groups: Group A, no prior exacerbations; Group B, 1 prior moderate exacerbation only; Group C, 1 prior severe exacerbation only; and Group D, ≥2 prior moderate and/or severe exacerbations.

b Adjusted model included the following baseline sociodemographic and clinical characteristics: sex, age, smoking status, cardiovascular disease, cerebrovascular disease, depression, and MRC dyspnoea score.

c Costs relative to Group A.

Figure 1. All-cause and COPD-related unadjusted mean cumulative costs by exacerbation history group^a at (a) 12, (b) 24 and (c) 36 months of follow-up.

COPD, chronic obstructive pulmonary disease; ER, emergency room; GP, general practitioner; GW, general ward; ICU, intensive care unit.

^aExacerbation history groups: Group A, no prior exacerbations; Group B, 1 prior moderate exacerbation only; Group C, 1 prior severe exacerbation only; and Group D, ≥2 prior moderate and/or severe exacerbations.

Data availability statement

Remote access to this dataset was provided to the study statisticians via Safe Haven. Due to the nature of this research, participants of this study did not agree for their data to be shared publicly, so supporting data are not available.