Small-cell lung cancer patients are just 'a little bit' tired: response shift and self-presentation in the measurement of fatigue.
BACKGROUND
Response shift has gained increasing attention in the measurement of health-related quality of life (QoL) as it may explain counter-intuitive findings as a result of adaptation to deteriorating health.


OBJECTIVE
To search for response shift type explanations to account for counter-intuitive findings in QoL measurement.


METHODS
Qualitative investigation of the response behaviour of small-cell lung cancer (SCLC) patients (n = 23) in the measurement of fatigue with The European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaire (EORTC QLQ-C30) question 'were you tired'. Interviews were conducted at four points during 1st line chemotherapy: at the start of chemotherapy, 4 weeks later, at the end of chemotherapy, and 6 weeks later. Patients were asked to 'think aloud' when filling in the questionnaire.


RESULTS
Fifteen patients showed discrepancies between their answer to the EORTC question 'were you tired' and their level of fatigue spontaneously reported during the interview. These patients chose the response options 'not at all' or 'a little' and explained their answers in various ways. In patients with and without discrepancies, we found indications of recalibration response shift (e.g. using a different comparison standard over time) and of change in perspective (e.g. change towards a more optimistic perspective). Patients in the discrepancy group reported spontaneously how they dealt with diagnosis and treatment, i.e. by adopting protective and assertive behaviour and by fighting the stigma. They distanced themselves from the image of the stereotypical cancer patient and presented themselves as not suffering and accepting fatigue as consequence of treatment.


CONCLUSIONS
In addition to response shift, this study suggests that 'self-presentation' might be an important mechanism affecting QoL measurement, particularly during phases when a new equilibrium needs to be found.
Westerman
Marjan J
MJ
Department of Public and Occupational Health, EMGO Institute, VU University Medical Centre, Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands. MJ.Westerman@vumc.nl
The
Anne-Mei
AM
Sprangers
Mirjam A G
MA
Groen
Harry J M
HJ
van der Wal
Gerrit
G
Hak
Tony
T
D000368:Aged; D018288:Carcinoma, Small Cell / Q000503:physiopathology* / Q000523:psychology; D003627:Data Interpretation, Statistical; D005221:Fatigue / Q000209:etiology / Q000523:psychology*; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D008175:Lung Neoplasms / Q000503:physiopathology* / Q000523:psychology; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D010865:Pilot Projects; D011446:Prospective Studies; D011594:Psychometrics / Q000295:instrumentation* / Q000706:statistics & numerical data; D011788:Quality of Life; D012650:Self Disclosure; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires