Journal of Rehabilitation Medicine 51-1CompleteIssue | Page 67

64
G. Müller et al.
study. A final total of 1,829 intervention participants
were included in the study (Fig. 1). Of the 2,444 con-
tacted insured persons, 978 agreed to join the control
group. After excluding 163 study participants, and
following matching, a total of 495 remained in the
control group (Fig. 1).
Adjustment of the control group with propensity
score matching for time t0 resulted in good compara-
bility of the treatment groups (Table IV). Except for
sex (χ 2 (1) (n = 2,319) = 4.66, p < 0.035), no significant
differences emerged and all standardized differences
were <0.1. Complete cost data were available for all
measurement time periods. The response rate for the
individual measurement points for questionnaire data
(GCPS) ranged between 64% (t6) and 51% (t4). The
study participants were preponderantly female (ST
64%, BE 58.6 %). The mean age was 46.8 years (ST
47.6 years, 95% confidence interval (95% CI) [46.5;
48.7]; BE 46.6 years, 95% CI [46.1; 47.2]). The mean
GCPS at t0 for ST and BE was 2.2 (ST: 2.18, 95% CI
[2.090; 2.274]; (BE: 2.201, 95% CI [2.153; 2.249])
(Table IV).
!
Costs
The direct medical costs for BE and ST did not differ
significantly during the intervention period (Table
VI). This reflects the higher exercise costs, amoun-
ting to 467 EUR, that each BE participant incurred
in addition to the medical costs. During the second
post-intervention year and for the entire period of the
intervention, the BE costs were significantly lower
than the ST costs (Fig. 2).
The higher direct medical costs for ST are due spe-
cifically to the cost areas for hospital charges and sick
pay (Table VII). Relevant for the cost picture are the
costs during the 2 years after intervention start: for
direct medical costs, direct back pain medical costs
(without exercise costs), and indirect medical costs,
the BE costs are significantly less
than the ST costs. The indirect
back pain medical costs from BE
ST participants (n= 2,444)
are not significantly different to
ST, even with the indirect costs
No consent form (n= 1,466)
of ST within the 2 years after
intervention being 30% higher
Exclusions (n= 483)
than for BE (Table VI).
Inclusion criteria not met (n= 108)
BE participants (n= 2,444)
No ! consent form (n=502)
Exclusions ! (n= 113)
Inclusion criteria not met (n= 6)
Missing ! cost data (n= 23)
Incomplete questionnaires t0 (n= 84)
Missing cost data (n= 16)
Incomplete questionnaires t0 (n= 39)
Not matched (n= 320)
!
!
Cost data analyzed (n= 1,829)
!
Questionnaire
data analyzed (n= 1,829) t0 Questionnaire data analyzed (n= 495)
! data analyzed (n= 1,829)
Cost
No survey response (n= 609)
!
Questionnaire data analyzed (n= 1,220) t1 Cost data analyzed (n= 495)
No survey response (n= 235)
Questionnaire data analyzed (n=260)
!
Cost data analyzed (n= 1,829)
! survey response (n= 754)
No
Questionnaire data analyzed (n= 1,075)
t2
!
Cost data analyzed (n= 1,829)
! survey response (n= 817)
No
Questionnaire data analyzed (n= 1,012)
t3
!
Cost data analyzed (n= 1,829)
!
No survey response (n= 901)
Questionnaire
data analyzed (n= 928)
!
Although the 2 last grades of the GCPS exclusively
reflect the severity of the functional impairment, the
pain intensity dimension, of course, nevertheless also
increases in both grades. The direct and indirect medi-
cal costs also increase with increasing GCPS (Table V).
t4
Cost data analyzed (n= 495)
No survey response (n= 219)
Questionnaire data analyzed (n= 276)
Cost data analyzed (n= 495)
No survey response (n= 232)
Questionnaire data analyzed (n= 263)
Cost data analyzed (n= 495)
No survey response (n= 239)
Questionnaire data analyzed (n= 256)
Fig. 1. Recruitment of study participants: exclusions, and questionnaire responses at each
measurement point (BE: intervention group “multimodal back exercise”, ST: control group
“standard treatment”).
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Therapeutic effects
BE significantly reduced the 2
back pain parameters (most se-
vere back pain, mean back pain)
and the function parameters (im-
pairment of daily work, days with
pain) (Table VIII). This resulted
in a significant reduction in the
mean value GCPS grade of 0.4
BE compared with ST (2 years
post-intervention) (Table VIII).
The group with moderate and
severe functional impairments
(grades 3 and 4) reduced in num-
ber by more than half during the
first year post-BE (pre-: 37.8%,
post-: 16.2%), while it remained
approximately unchanged for ST
(pre-: 35.6%, post-: 37%; Table
VIII). After 2 years post-BE, the
share of grades 3 and 4 also de-
creased for the ST group, by 25%