Validation of a core patient-reported-outcome measure set for operationalizing success in multimodal pain therapy: useful for depicting long-term success?

Cross-cultural adaptation and validation of the German Central Sensitization Inventory (CSI-GE)

BACKGROUND

The Central Sensitization Inventory (CSI) is a screening tool designed to detect symptoms related to Central Sensitization (CS) and Central Sensitivity Syndromes (CSS) by measuring the degree of related phenomena. The objective of this study was to create a German, culturally-adapted version of the CSI and to test its psychometric properties.

METHODS

A German version of the CSI (CSI-GE) was developed, culturally-adapted, and pretested for comprehensibility. The psychometric properties of the resulting version were validated in a clinical study with chronic pain and pain-free control subjects. To assess retest reliability, the CSI-GE was administered twice to a subgroup of patients. Structural validity was tested using factor analyses. To investigate construct validity a hypotheses testing approach was used, including (1) correlations between the CSI-GE and several other well-established questionnaires as well as (2) an investigation of the CSI-GE discriminative power between different subgroups of participants believed to have different degrees of CS.

RESULTS

The CSI-GE showed excellent reliability, including high test-retest characteristics. Factor analyses confirmed a bi-factor dimensionality as has been determined previously. Analysing construct validity 6 out of 11 hypotheses (55%) were met. CSI-GE scores differentiated between subgroups according to expectations. Correlations between CSI-GE scores and other questionnaires suggested that none of the correlated constructs was identical, but there was overlap with other questionnaires based on symptom load. Several correlations did not fit with our current understanding of CS.

CONCLUSION

The CSI-GE appears to be a reliable tool for measuring CS/CSS-related symptomatology. Whether this implies that the CSI-GE measures the degree of CS within an individual subject remains unknown. The resulting score should be interpreted cautiously until further clarification of the construct.

Access to Pain Management Programs: A Multifactorial Analysis of the Pathways of Care for Chronic Pain Patients in the University Clinic Erlangen

BACKGROUND

Different treatment options are offered for patients suffering from chronic pain, which differ in intensity and costs: 1) monodisciplinary treatment, mostly in outpatient care and 2) interdisciplinary treatment with the option of participating in pain management programs as outpatients or inpatients. The present work investigates how patients at the University Clinic Erlangen receiving monodisciplinary treatment differ from those receiving interdisciplinary treatment (research question I) as well as how patients participating in a pain management program differ from those who do not (research question II). The aim is to generate insights into whether the differences between the patient groups under various treatment modalities reflect the officially defined criteria for the indication of chronic pain management programs.

METHODS

Routine data of 1,833 patients treated from January 2008 to March 2013 at the University Clinic Erlangen were analyzed. After univariate preanalyses and checks for multicollinearity, the remaining variables were used for the final multivariate model (multiple binary logistic regression) for research question I and II.

RESULTS

Research question I: Patients getting interdisciplinary treatment were more often employed, had higher affective experience of pain, more often regarded their pain as treatable, had more often participated in at least one pain-associated rehabilitation treatment in the past, were younger and rarely had application for retirement in consideration. Research question II: Patients who participated in a pain management program were more often female, more often employed, described their pain as mainly located at the upper part of the body, had more concomitant symptoms, were more often diagnosed with musculoskeletal pain and rarely had a retirement request pending.

CONCLUSIONS

It could be shown that patients in the analyzed pathways of care mainly differed in demographic variables, and regarding pain management programs, also in the type of pain. Differences between patients in different treatment paths reflecting the officially defined indication criteria for chronic pain management programs were detectable only to a minor extent. Clearer and operational practical guidance should help support the clinical decision to assign patients to different treatment options and close the gap between theory and practice.