Table 4

Regression model estimating the influence of patient characteristics on (A) changes in health utilisation after switch, and (B) changes in costs after switch. Models include interaction term ‘after’ and adjusting variables†

		Interaction term
		After*gender (Male=1)		After*age/year		After*ETA duration‡
		Exp (estimate)	P value	Exp (estimate)	P value	Exp (estimate)	P value
(A) Changes in health utilisation per patient
Inpatient services	Number of inpatient admissions	0.98 (0.64–1.48)	0.907	1.01 (0.99–1.03)	0.208	1.11 (0.97–1.27)	0.136
Inpatient services	Number of days in hospital	0.83 (0.40–1.73)	0.622	1.02 (0.99–1.04)	0.200	1.12 (0.87–1.43)	0.392
Outpatient	Number of outpatient visits	1.01 (0.95–1.07)	0.826	1.00 (1.00–1.00)	0.841	1.07 (1.05–1.19)	<0.0001
Medication	Pain medication, DDD	1.01 (0.94–1.09)	0.777	1.00 (0.99–1.00)	0.763	1.01 (0.99–1.04)	0.293
	Other medication	0.98 (0.93–1.03)	0.431	1.00 (0.99–1.00)	0.383	1.00 (0.98–1.02)	0.767
	Total	0.98 (0.94–1.03)	0.477	1.00 (0.99–1.00)	0.344	1.01 (0.99–1.02)	0.571
(B) Changes in health costs per patient
Inpatient services	Diseases of the musculoskeletal system and connective tissue	0.61 (0.23–1.61)	0.321	1.03 (1.00–1.05)	0.066	1.19 (0.88–1.66)	0.251
	Other diseases	0.99 (0.58–1.72)	0.984	1.03 (1.01–1.05)	0.002	1.00 (0.82–1.21)	0.966
	Total	0.97 (0.60–1.58)	0.903	1.03 (1.01–1.04)	0.002	1.02 (0.87–1.21)	0.784
Outpatient services	Diseases of the musculoskeletal system and connective tissue	1.08 (0.98–1.19)	0.126	1.00 (0.99–1.00)	0.976	1.04 (1.00–1.08)	0.072
	Other diseases	1.15 (0.89–1.48)	0.284	1.00 (0.99–1.01)	0.304	1.10 (1.01–1.19)	0.028
	Total	1.08 (0.99–1.18)	0.093	1.00 (1.00–1.00)	0.521	1.04 (1.00–1.08)	0.036
Primary sector	General practitioner	1.07 (0.98–1.16)	0.153	1.00 (1.00–1.00)	0.682	1.04 (1.01–1.08)	0.007
	Other practicing specialist	1.04 (0.80–1.36)	0.756	1.00 (0.99–1.01)	0.668	0.99 (0.89–1.09)	0.810
	Physiotherapist, chiropractor, foot specialist	1.02 (0.91–1.15)	0.705	1.00 (1.00–1.00)	0.256	0.99 (0.95–1.04)	0.754
	Other	1.06 (0.90–1.24)	0.484	1.00 (0.99–1.00)	0.719	0.98 (0.92–1.04)	0.465
	Total	1.05 (0.98–1.13)	0.176	1.00 (1.00–1.00)	0.423	1.00 (0.98–1.03)	0.769
Medication§	Pain medication	0.99 (0.88–1.10)	0.823	1.00 (1.00–1.00)	0.957	1.03 (0.99–1.07)	0.119
	Other medication	0.94 (0.85–1.04)	0.214	1.00 (0.99–1.00)	0.375	1.00 (0.97–1.04)	0.835
	Total	0.96 (0.88–1.04)	0.287	1.00 (1.00–1.00)	0.404	1.01 (0.98–1.03)	0.513
Total costs		1.03 (0.94–1.14)	0.516	1.00 (1.00–1.01)	0.085	1.03 (0.99–1.07)	0.146

Statistically significant results are marked with bold types.
†Adjusted for gender, age, dead in post period, duration of ETA before index date, stopped SB4 treatment within 180 days and comorbidities 12–24 months before index date.
‡ETA duration as categories.
§Medication handled by prescription included (ETA, SB4 not included).