A prospective, multisite, international validation of the Complex Regional Pain Syndrome Severity Score

Abstract

Clinical diagnosis of complex regional pain syndrome (CRPS) is a dichotomous (yes/no) categorization, a format necessary for clinical decision making. Such dichotomous diagnostic categories do not convey an individual's subtle gradations in the severity of the condition over time and have poor statistical power when used as an outcome measure in research. This prospective, international, multicenter study slightly modified and further evaluated the validity of the CRPS Severity Score (CSS), a continuous index of CRPS severity. Using a prospective design, medical evaluations were conducted in 156 patients with CRPS to compare changes over time in CSS scores between patients initiating a new treatment program and patients on stable treatment regimens. New vs stable categorizations were supported by greater changes in pain and function in the former. Results indicated that CSS values in the stable CRPS treatment group exhibited much less change over time relative to the new treatment group, with intraclass correlations nearly twice as large in the former. A calculated smallest real difference value revealed that a change in the CSS of ≥4.9 scale points would indicate real differences in CRPS symptomatology (with 95% confidence). Across groups, larger changes in CRPS features on the CSS over time were associated in the expected direction with greater changes in pain intensity, fatigue, social functioning, ability to engage in physical roles, and general well-being. The overall pattern of findings further supports the validity of the CSS as a measure of CRPS severity and suggests it may prove useful in clinical monitoring and outcomes research.

A multi‐centre study to explore the feasibility and acceptability of collecting data for complex regional pain syndrome clinical studies using a core measurement set: Study protocol

“…The data collection tools comprise two documents: The patient reported COMPACT questionnaire set, completed at baseline and at 6 months, comprising standardized outcome measures (Table ). Where applicable, we have obtained permission from the distributors or licence holders to use the standardized questionnaires for the purposes of this study. The CRPS Severity Score (CSS) (Harden et al, ). This will be completed by the clinician and is directly derived from the Budapest CRPS diagnostic criteria (Harden et al, ).…”

“…Where applicable, we have obtained permission from the distributors or licence holders to use the standardized questionnaires for the purposes of this study. The CRPS Severity Score (CSS) (Harden et al, ). This will be completed by the clinician and is directly derived from the Budapest CRPS diagnostic criteria (Harden et al, ). This is a routine data collection tool that is used by a clinically qualified healthcare professional to confirm the diagnosis of CRPS.…”

“…Patient‐reported symptoms and CRPS signs present on examination by the clinician are recorded by the clinician and added to give a total. Higher scores indicate greater CRPS severity (range 0–16) (Harden et al, ).…”

“…The defined measures captured the domains within the overarching research question: “What is the clinical presentation and course of CRPS and what factors influence it?”, and comprised: pain, disease severity, participation and function, emotional and psychological function, self‐efficacy, catastrophizing and patient's global impression of change (Grieve et al, ). One clinician‐reported measure captured the severity of CRPS (Harden et al, ). A Delphi study, led by consortium members, is currently being conducted to define the core clinical outcome measures which will be included in the registry but this is not described in the present protocol.…”

Advancing Transcranial Magnetic Stimulation Methods for Complex Regional Pain Syndrome: An Open-Label Study of Paired Theta Burst and High-Frequency Stimulation

“…Prior to treatment, we characterized each patient by collecting medical history, administering pain‐related questionnaires, and administering a CRPS assessment to confirm the diagnosis. A trained clinical researcher evaluated participants using the CRPS Severity Score, a validated tool as described by Harden et al to determine the presence or absence of the following signs and symptoms: hyperalgesia, mechanical allodynia, temperature asymmetry, color asymmetry, asymmetric edema, sweating asymmetry, dystrophic changes in the hair/nails/skin, and finally motor abnormalities including tremor, dystonia, weakness, decreased range of motion. Average daily pain ratings using a 0–10 visual analog scale (VAS) were collected prospectively on a daily basis for at least three days prior to the first day of treatment to establish an average baseline level of pain in the CRPS‐affected limb.…”