Rehabilitation Research and Practice

Research Article

Cost of Illness for Patients with Arthritis Receiving Multidisciplinary Rehabilitation Care

Table 5

(a) The influence of clinical subgroup, age, gender, comorbidity, and work status on total health care costs (sum of cost groups 1 to 3 for rehabilitation period and 6 months after) for patients with inflammatory disease. The results are presented as Unstandardised Coefficients () with 95% Confidence intervals


Variable	Model 1	Model 2	Model 3	Model 4

Clinical subgroup

Inflammatory disease rehab center	Ref.	Ref.	Ref.	Ref.

Inflammatory disease inpatient hospital unit	13,412 (8,744 to 18,080)**	12,952 (8,299 to 17,605)**	12,935 (8,173 to 17697)**	13,721 (8,806 to 18,635)**

Inflammatory disease outpatient hospital unit	−2,595 (−9,388 to 4,196)	−2,406 (−5,875 to 3,727)	−2,560 (−9,514 to 4,395)	−73 (−7,089 to 6,940)

Gender (ref. female) Male	−2,968 (−8,055 to 2,118)	−3,272 (−8,371 to 1,826)	−3,555 (−8,744 to 1,633)*	−4,025 (−9,402 to 1,352)

Age (ref. 67 or less) 68+	1,682 (−4,712 to 8,077)	1,843 (−4,583 to 8,271)	4,430 (−1,762 to 10,624)	4,045 (−2,379 to 10,469)

Comorbidity (ref. none)
One	3,170 (−2,373 to 8,714)	3,291 (−2,282 to 8,864)	3,795 (−1,849 to 9,439)	4,851 (−1,002 to 10,632)
Two or more	2,939 (−2,830 to 8,708)	2,274 (−3,457 to 8,005)	2,885 (−3,003 to 8,775)	3,346 (−2,759 to 9,452)

Working status (ref. employed) Not employed	1,732 (−3,288 to 6,753)	1,716 (−3,333 to 6,765)	448 (−4,589 to 5,485)	402 (−4,827 to 5,632)

MHAQ	−5,179 (−12,174 to 1,815)	—	1,151 (−4,092 to 6,396)	4,122 (−921 to 9,166)*

SF Physical function	−172 (−301 to −42)**	−106 (−202 to −11)*	—	—

SF Mental function	−1 (−21to 19)	41 (−21 to 19)	—	—

Assistive tools	1,447 (414 to 2,540)**	1,315 (268 to 2,361)*	1,619 (542 to 2,695)**	—

Constant	16,367 (4,568 to 28,168)**	10,292 (10763 to 18,819)**	3,367 (−3,134 to 9,869)	2,178 (−4,522 to 8,878)

Adj R-squared	0.3593	0.3518	0.3276	0.2750

Cost values (in Euro) are estimated means by OLS. All costs are presented in Euros: 1€ = 8 NOK.
* P-value < .05, **P-value < .01.
The difference between the three models is only the inclusion of different severity measures in addition to clinical setting, diagnosis, age, gender, and working status.
Model 1: all severity measures are included: MHAQ, SF36 Physical function, SF36 Mental function, and assistive tools.
Model 2: we include only SF36 Physical function, SF36 Mental function and assistive tools.
Model 3: we include only MHAQ and assistive tools.
Model 4: we include only MHAQ.

(b) The influence of clinical subgroup, age, gender, comorbidity, and work status on total health care costs (sum of cost groups 1 to 3 for rehabilitation period and 6 months after) for patients with osteoarthritis (OA). The results are presented as Unstandardised Coefficients () with 95% Confidence intervals


Variable	Model 1	Model 2	Model 3	Model 4

Clinical subgroup

OA (ref. conventional rehabilitation)	Ref.	Ref.	Ref.	Ref.

OA postsurgery rehabilitation	−675 (−2,664 to 1,313)	−220 (−2,135 to 1,694)	−683 (−2,658 to 1,290)	−57 (−2,723 to1,207)

Gender (ref. female) Male	−2,086 (−4,166 to −6)*	−2,037 (−4,125 to −50)	−2,103 (−4,142 to −65)*	1,915 (−3,903 to 72)

Age (ref. 67 or less) 68+	651 (−1,282 to 2585)	386 (−1,527 to 2,300)	693 (−1,217 to 2,605)	578 (−1,312 to 2,468)

Comorbidity (ref. none)
One	1,054 (−1,445 to 3,554)	1,080 (−1,429 to 3,590)	1,178 (−1,265 to 3,622)	1,148 (−1,292 to 3,589)
Two or more	1,341 (−1,160 to 3,842)	1,470 (−1,036 to 3,977)	1,514 (−891 to 3,920)	1,507 (−335 to 3,163)

Working status (ref. employed) Not employed	192 (−1,805 to 2,190)	−34 (−2,020 to 1,951)	263 (−1,707 to 2,234)	128 (−1,814 to 2,072)

MHAQ	1,512 (−365 to 3,390)	—	1,614 (−199 to 3,428)	1,414 (−335 to 3,163)

SF Physical function	−2 (−13 to 9)	−4 (−15 to 6)	—	—

SF Mental function	−1 (−9 to 6)	−2 (−9 to 6)	—	—

Assistive tools	−216 (−738 to 305)	−106 (−612 to 399)	−220 (−739 to 299)	—
Constant	6,592 (3,301 to 9,882)**	7,650 (4,621 to 10,679)**	6,158 (3,303 to 9,013)**	6,244 (3,399 to 9,090)**

Adj R-squared	0.0101	0.0128	0.0193	0.0209

Cost values (in Euro) are estimated means by OLS. All costs are presented in Euros: 1€ = 8 NOK.
* -value < .05, **-value < .01.
The difference between the three models is only the inclusion of different severity measures in addition to clinical setting, diagnosis, age, gender and working status.
Model 1: all severity measures are included: MHAQ, SF36 Physical function, SF36 Mental function, and assistive tools.
Model 2: we include only SF36 Physical function, SF36 Mental function, and assistive tools.
Model 3: we include only MHAQ and assistive tools.
Model 4: we include only MHAQ.