3.2. The Patients’ Perceived Treatment Helpfulness at Discharge
As presented in Figure 1
, 75% (n
= 208) of the patients completing the program rated the MPMP in general as helpful. Mean perceived helpfulness was 4.39 ± 1.23.
Among the different treatments, the vast majority of patients considered group-based physiotherapy (PTg, n = 241, 87.3%) and individual physiotherapy as being helpful (PTi, n = 236, 85.5%). On average, both group- and individual-based physiotherapy were perceived as very helpful (PTg: 4.87 ± 1.14, PTi: 5.0 ± 1.2). Importantly, almost half of the patients (n = 134, 48.6%) reported that individually-delivered physiotherapy was extremely helpful to alleviate CBP. Similarly, a high percentage of patients (n = 106, 38.4%) also rated group-based physiotherapy as extremely helpful. Following physiotherapy, most of the patients considered relaxation therapy (n = 216, 78.3%), aquatic therapy (n = 215, 77.9%) and back education (n = 207, 75.0%) as beneficial. The mean perceived helpfulness of relaxation therapy (4.6 ± 1.27), aquatic therapy (4.54 ± 1.37) and back education (4.43 ± 1.3) was moderately or very helpful. In contrast, the mean helpfulness of medical training therapy (3.38 ± 1.51), biofeedback (3.31 ± 1.48), psychological pain therapy (3.15 ± 1.42) and music therapy (3.02 ± 1.47) ranged between slightly and moderately helpful. Less than two-thirds of the patients consider medical training therapy (n = 147, 53.3%), biofeedback (n = 170, 61.6%), psychological pain therapy (n = 176, 63.8%) or music therapy (n = 181, 65.6%) to be beneficial in reducing CBP.
In summary, mean patient-perceived helpfulness ranged from 5 (±1.2) for individually-delivered physiotherapy to 3.02 (±1.47) for music therapy (Figure 2
). In fact, mean helpfulness of the different treatments was ranked as follows: (1) individual physiotherapy; (2) group-based physiotherapy; (3) relaxation therapy; (4) aquatic therapy; (5) back education; (6) medical training therapy; (7) biofeedback; (8) psychological pain therapy; (9) music therapy. Detailed information (frequencies, means, percent, SEM, SD) are provided in Tables S1 and S2
3.3. Influence of Sociodemographic Characteristics on the Patients’ Perceived Helpfulness
Pain location did not influence the perceived helpfulness of different treatments. Neither patients with lower or upper back pain nor participants suffering from both showed differences in their perspective on treatments helping to alleviate CBP. Similarly, smoking status was not correlated with the patients’ perceived helpfulness.
Significant but generally weak correlations with small effect sizes (Spearman’s rho) were found between several treatments and sociodemographic/pain-related characteristics (Table S3
). A reciprocal correlation exists between pain chronicity and perceived helpfulness of the MPMP in general (rs
= −0.158; p
= 0.009) indicating higher helpfulness ratings for patients with a lower level of chronicity. Furthermore, a weak correlation was found between chronicity status and back education treatment (rs
= −0.120; p
= 0.046) suggesting that patients with higher stages of chronic pain might favor back education training.
A significant correlation was also observed between age and psychological pain therapy (rs = 0.147; p = 0.015) indicating that older patients tend to consider psychological interventions as more helpful. In contrast, the older the patient the less helpful device-assisted strength training (medical training therapy) was perceived (rs = −0.189; p = 0.002).
Moreover, there were weak but significant correlations between the level of education and the perceived helpfulness of medical training therapy (rs = 0.133, p = 0.028), psychological pain therapy (rs = −0.153, p = 0.011) and music therapy (rs = −0.132, p = 0.029). This suggests that the higher the education, the more likely patients were to perceive medical training therapy as helpful. The lower the education, the more likely patients were to perceive psychological and music therapies as helpful.
Patients with higher BMI scores rated aquatic (rs = 0.148, p = 0.014) and psychological pain therapies (rs = 0.122, p = 0.043) as more helpful than did those with lower BMI scores.
In addition, the lack of regular sporting activity prior to the program correlates with increasing helpfulness ratings for medical training therapy. Thus, patients who did not participate in regular sports activities before study entry seem to perceive medical training therapy as being helpful to reduce CBP (rs = −0.139, p = 0.021) when compared to patients who worked out on a regular basis.
3.4. The Multidisciplinary Pain Management Program Reduces Pain-Related Complaints
highlights the changes of pain-related outcome parameters during the three-week MPMP. As illustrated, pain intensities (NRS), pain related disability (PDI) and levels of depressive symptoms (ADS-L) were significantly reduced after completing the program (T1) when compared to study entry (T0). For detailed information about the results of the Wilcoxon signed-rank test including Z-values, see Table S4
Except for the FFbH-R, large effect sizes for changes in pain-related outcome parameters were observed. Mean pain intensity decreased from 5.24 ± 2.08 at study entry to 3.80 ± 2.02 (Z = −10.164, p < 0.001, η2 = 0.374). Similarly, worst, least and current pain significantly improved from 6.97 ± 2.13 to 5.8 ± 2.35 (worst pain Z = −8.204, p < 0.001, η2 = 0.244), 2.77 ± 1.93 to 1.95 ± 1.85 (least pain Z = −8.042, p < 0.001, η2 = 0.234) and from 4.41 ± 2.42 to 3.07 ± 2.37 (current pain Z = −9.134, p < 0.001, η2 = 0.302), respectively. Besides pain intensities, a 10% decrease from baseline was observed for the PDI score (T0: 26.7 ± 12.27; T1: 17.4 ± 11.78; Z = −12.387, p < 0.001, η2 = 0.556) and the mean ADS-L score dropped significantly from 19.43 ± 9.53 to 9.77 ± 8.27 (Z = −12.592, p < 0.001, η2 = 0.574). Treatment-induced changes in average pain intensity, pain induced disability (PDI) and depressive symptoms (ADS-L) were clinically meaningful, demonstrating the efficacy of the program. Interestingly, despite these improvements in pain-related complaints functional ability (FFbH-R) significantly decreased with a medium sized effect from 74.54% ± 16.89 to 71.49% ± 15.07 (Z = −4.198, p < 0.01, η2 = 0.064) during the study. Analgesic intake was not influenced by the program.
3.5. The Patients’ Perspective Corresponds to Pain-Related Treatment Outcomes
To assess associations between the subjective evaluation of treatment helpfulness by the patients and changes in objectively measured outcome parameters, helpfulness ratings were dichotomized (≥ 4 helpful vs. < 4 not helpful) and analyzed in relation to changes in pain-related treatment outcome. Accordingly, Table 5
illustrates the effects of the dichotomized patients’ perceived treatment helpfulness on changes (delta Δ) in pain, physical and psychosocial functioning. For more detailed information regarding the statistical analyses, see Tables S5–S8
Patients reporting that the MPMP in general helped to reduce back pain indeed showed significant decreases in Δ pain values during this study compared to those considering the program as not being helpful (Δ pain average p < 0.001, CI = −1.431 to −0.386; Δ pain worst p < 0.001, CI = −1.808 to −0.674; Δ pain least p = 0.003, CI = −0.995 to −0.095; Δ pain current p= 0.004, CI = −1.461 to −0.262). Thus, the patients’ perspective on the helpfulness of different treatments significantly corresponds to the degree of pain improvement. Furthermore, perceiving the program as helpful was associated with reduced levels of pain-related disability (Δ PDI, p = 0.005, CI = −6.518 to −1.218). Calculated effect sizes ranged from small (η2 < 0.06) to medium (Δ pain average η2 = 0.060 and Δ pain worstη2 = 0.067).
Surprisingly, the analyses revealed no relationship between the perceived helpfulness of individual physiotherapy and changes in pain-related characteristics (Δ pain intensities, Δ PDI, Δ FFbH-R, Δ ADS-L). Thus, participants experiencing individual physiotherapy as helpful did not show a greater degree of improvements in pain-related parameters when compared to patients that did not consider individual physiotherapy as being helpful to reduce CBP. Strikingly, on average, individual physiotherapy was rated as very helpful and ranked highest among the treatments.
In contrast to individually-delivered physiotherapy, patients considering group-based physiotherapy as helpful in decreasing CBP showed significantly higher degrees of improvement in pain intensities and disability than patients rating group-based physiotherapy as not helpful (Δ pain average p < 0.001, CI = −2.084 to −0.744; Δ pain worst p < 0.001, CI = −2.146 to −0.666; Δ pain least p = 0.01, CI = −1.295 to −0.131; Δ pain current p = 0.006, CI = −1.854 to −0.300; Δ PDI p < 0.001, CI = −10.111 to −3.331). All measured effect sizes were small except of Δ pain average with a medium effect size of η2 = 0.069.
After completion of the program a significantly greater degree of reduction in pain intensities with small effect sizes was observed for patients rating relaxation therapy as helpful in contrast to patients that consider relaxation therapy not helpful (Δ pain average p = 0.015, CI= −1.235 to −0.132; Δ pain worst p = 0.01, CI = −1.397 to −0.188; Δ pain least p = 0.005, CI = −1.136 to −0.200; Δ pain current p = 0.005, CI = −1.530 to −0.278).
Patients reporting aquatic therapy to be beneficial in reducing pain showed a higher degree of improvement in pain worst only (p = 0.045, CI = −1.077 to 0.135), when compared to the 22.1% of the study population that rated aquatic therapy as not helpful. The effect size for this association was small.
The degree of improvements in pain intensities was significantly greater in patients perceiving back education as helpful treatment when compared to the 25% of the study population that rated back education as not helpful (Δ pain average p < 0.001, CI = −1.428 to −0.388; Δ pain worst p < 0.001, CI = −1.627 to −0.489; Δ pain least p = 0.019, CI = −0,984 to −0.089; Δ pain current p = 0.030, CI = −1.267 to −0.067). MANOVA revealed only small effect sizes.
For patients evaluating medical training therapy as helpful the degree of average and worst pain reduction as well as the decrease of PDI was significantly higher than for the 46.7% of the study population experiencing medical training therapy as not helpful (Δ pain average p = 0.016, CI = −0.979 to −0.066; Δ pain worst p < 0.001, CI = −1.284 to −0.289; Δ PDI p = 0.014, CI = −5.560 to −0.980). Again, effect sizes were small.
Significant associations with small effect sizes were found between the perceived helpfulness of biofeedback and changes in pain-related outcome parameters. Rating biofeedback as helpful was related to a higher degree of improvements in pain intensities and the PDI when compared to patients reporting that biofeedback did not help to reduce CBP (Δ average pain p = 0.003, CI = −1.169 to −0.238; Δ worst pain p = 0.003, CI = −1.276 to −0.254; Δ least pain p = 0.025, CI = −0.856 to −0.058; Δ current pain p = 0.033, CI = −1.115 to −0.046; Δ PDI p = 0.011, CI = −5.426 to −0.716).
With small effect sizes, improvements of worst pain intensity were significantly greater in patients considering psychological pain therapy as being helpful to ameliorate CBP when compared to participants perceiving this treatment modality as not helpful (p = 0.045, CI = −1.054 to −0.011).
Patients reporting that music therapy helps to alleviate CBP did not show any changes in pain-related characteristics when compared to the participants rating music therapy as not helpful.
Importantly, patients’ perspective on the helpfulness of different treatment modalities also corresponds to changes in the FFbH-R with small effect sizes. However, MANOVA-pairwise comparisons revealed that rating treatments as helpful was significantly associated with a higher degree of impairment in pain-related functional ability. Thus, considering the following treatments as not helpful corresponds to a significantly lesser decrease in back function (program in general p < 0.001, CI = 6.408 to 16.919; group-based physiotherapy p < 0.001, CI = 9.661 to 23.185; aquatic therapy p = 0.036, CI = 2.011 to 13.155; back education p = 0.002, CI = 3.164 to 13.792; music therapy p = 0.005, CI = 2.104 to 11.823; biofeedback p = 0.004, CI = 2.182 to 11.671; medical training therapy p = 0.002, CI = 3.036 to 12.246).