Response Shift After Cognitive Behavioral Therapy Targeting Severe Fatigue: Explorative Analysis of Three Randomized Controlled Trials

International Journal of Behavioral Medicine, vol. 30, pp. 473–485

Abstract

BACKGROUND: Cognitive behavioral therapy (CBT) is an evidence-based intervention for severe fatigue. Changes in patients' fatigue scores following CBT might reflect not only the intended relief in fatigue but also response shift, a change in the meaning of patients' self-evaluation. Objectives were to (1) identify the occurrence of response shift in patients undergoing CBT, (2) determine the impact of response shift on the intervention effect, and (3) investigate whether changes in fatigue-related cognitions and perceptions, targeted during CBT, are associated with response shift. METHODS: Data of three randomized controlled trials testing the efficacy of CBT in individuals with chronic fatigue syndrome (CFS, n = 222), cancer (n = 123), and diabetes (n = 107) were re-analyzed. Fatigue severity was measured with 8 items from the Checklist Individual Strength, a valid and widely used self-report questionnaire. Structural equation modelling was applied to assess lack of longitudinal measurement invariance, as indication of response shift. RESULTS: As expected, in all three trials, response shift was indicated in the CBT groups, not the control groups. Response shift through reprioritization was indicated for the items "Physically, I feel exhausted" (CFS) and "I tire easily" (cancer, diabetes), which became less vs. more important to the measurement of fatigue, respectively. However, this did not affect the intervention effects. Some changes in cognitions and perceptions were associated with the response shifts. CONCLUSIONS: CBT seems to induce response shift through reprioritization across patient groups, but its occurrence does not affect the intervention effect. Future research should corroborate these findings and investigate whether patients indeed change their understanding of fatigue.

Authors 7

1. Mathilde G. E. Verdam Aachen Institute of Psychology Department of Methodology and Statistics

   Leiden University · Amsterdam UMC Location University of Amsterdam · Amsterdam Public Health

   Affiliation as printed

   Amsterdam Public Health, Personalized Medicine, Amsterdam, The Netherlands

   Institute of Psychology, Department of Methodology and Statistics, Leiden University, Pieter de la Court Building, Wassenaarseweg 52, 2333 AK, Leiden, The Netherlands

   Medical Psychology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands

2. Frans Jeroen Oort

   University of Amsterdam

   Affiliation as printed

   Research Institute of Child Development and Education, University of Amsterdam, Nieuwe Achtergracht 127, 1018 WS, Amsterdam, The Netherlands

3. Heleen M. Riper

   Amsterdam Public Health · Vrije Universiteit Amsterdam · Amsterdam UMC Location Vrije Universiteit Amsterdam

   Affiliation as printed

   Amsterdam Public Health, Mental Health, Amsterdam, The Netherlands

   Department of Clinical, Neuro-, & Developmental Psychology, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands

   Department of Psychiatry, Amsterdam UMC Location Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands

4. Annemieke van Straten

   Amsterdam Public Health · Vrije Universiteit Amsterdam

   Affiliation as printed

   Amsterdam Public Health, Mental Health, Amsterdam, The Netherlands

   Department of Clinical, Neuro-, & Developmental Psychology, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands

5. Irma M. Verdonck‐de Leeuw

   Amsterdam Public Health · Vrije Universiteit Amsterdam · Amsterdam UMC Location Vrije Universiteit Amsterdam

   Affiliation as printed

   Amsterdam Public Health, Mental Health, Amsterdam, The Netherlands

   Department of Clinical, Neuro-, & Developmental Psychology, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands

   Department of Otolaryngology-Head and Neck Surgery, Amsterdam UMC Location Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands

6. Mirjam A. G. Sprangers

   Amsterdam UMC Location University of Amsterdam · Amsterdam Public Health · Cancer Center Amsterdam

   Affiliation as printed

   Aging & Later Life, Amsterdam Public Health, Amsterdam, The Netherlands

   Amsterdam Public Health, Mental Health, Amsterdam, The Netherlands

   Cancer Center Amsterdam, Cancer Treatment and Quality of Life, Amsterdam, The Netherlands

   Medical Psychology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands

7. Hans Knoop

   Amsterdam UMC Location University of Amsterdam · Amsterdam Public Health · Cancer Center Amsterdam · Amsterdam UMC Location Vrije Universiteit Amsterdam

   Affiliation as printed

   Amsterdam Public Health, Mental Health, Amsterdam, The Netherlands

   Cancer Center Amsterdam, Cancer Treatment and Quality of Life, Amsterdam, The Netherlands

   Expert Center for Chronic Fatigue, Amsterdam UMC Location Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands

   Medical Psychology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands