Feasibility, psychometric performance, and stability across modes of administration of the CARES-SF

BACKGROUND:: The primary objective was to investigate the validity and reliabilityof the Cancer Rehabilitation Evaluation System-Short Form (theCARES-SF) as a quality of life instrument in clinical trials[10]. PATIENTS AND METHODS:: A heterogeneous sample of 485 cancer patients completed theCARES-SF before treatment (T1), one month later (T2), and threemonths following T2 (T3). At T3 the patients completed the questionnaireeither by mail, in a telephone interview, or in the clinic.A sub sample of patients completed the CARES-SF a fourth time(T4) one week following T3, for purposes of test-retest reliabilityestimation. RESULTS:: On average, the CARES-SF required 11 minutes for completionand could be completed by 90% of the patients without assistance.However, 82% of the patients re ported difficulty with at leastone item. Multitrait scaling analysis and factor analysis generallyconfirmed the hypothe-sized scale structure. Internal consistencyreliability coefficients exceeded the 0.70 criterion for fourof six multi-item scales. The test-retest reliability coefficientsof the six scales were above 0.70. No systematic differenceswere found in the psychometrics of the CARES-SF across administrationconditions. In the mail condition the proportion of missingitems was significantly higher, and patients reported havingsignificantly more problems than in both the telephone and in-clinic condition. According to expectation, selective scalesdistinguished clearly between patients differing in diseasestage, performance status, treatment modality and tumor response.Additionally, selective scales were responsive to changes inhealth status over time. CONCLUSION:: These results lend support to the reliability and validity ofthe CARES-SF in assessing the quality of life of patients withcancer. At the same time, efforts to refine the questionnaireare recommended. Cancer, CARES-SF, quality of life, validation     

A study of the reliability,validity and responsiveness of the HIV Overview of Problems Evaluation System (HOPES) in assessing the quality of life of patients with AIDS and symptomatic HIV infection

The objective of this study was to evaluate the feasibility, reliability, validity and responsiveness of the HIV Overview of Problems Evaluation System (HOPES) in a Dutch sample. The HOPES was administered three times in a one-year period to a sample of 106 outpatients with a symptomatic HIV-infection (n=23) or AIDS (n=83). The HOPES is a self-report HIV-specific quality of life (QOL) questionnaire including five scales: physical, psychosocial and sexual functioning, medical interaction and partner relationship. QOL was also assessed with the EORTC Quality of Life Questionnaire (EORTC QLQ-C30), a 30-item self-report instrument. Clinical data included Centers for Disease Control and Prevention (CDC) stage, date of diagnosis and CD4 cell count. Patients needed approximately 20–30 minutes to complete the questionnaire. The five scales had good internal consistency reliability. Multitrait scaling analysis provided moderate support for item discriminant and convergent validity. The HOPES exhibited adequate levels of construct validity: (1) the inter-scale correlations and correlations with the EORTC QLQ-C30 were in the predicted direction; (2) it discriminated clearly between patients with AIDS and ARC and (3) it was able to document changes in QOL over time. Moreover, the HOPES was responsive to changes in clinical status over time as indicated by CD4 counts. This study provides further evidence of the reliability and validity of the HOPES and shows that this instrument is responsive to changes in CD4 cell counts.This research was made possible by a grant from the Dutch Ministry for Welfare, Public Health and Culture (grant no. 88-52).     

An application of structural equation modeling to detect response shifts and true change in quality of life data from cancer patients undergoing invasive surgery

The objective is to show how structural equation modeling can be used to detect reconceptualization, reprioritization, and recalibration response shifts in quality of life data from cancer patients undergoing invasive surgery. A consecutive series of 170 newly diagnosed cancer patients, heterogeneous to cancer site, were included. Patients were administered the SF-36 and a short version of the multidimensional fatigue inventory prior to surgery, and 3 months following surgery. Indications of response shift effects were found for five SF-36 scales: reconceptualization of general health, reprioritization of social functioning, and recalibration of role-physical, bodily pain, and vitality. Accounting for these response shifts, we found deteriorated physical health, deteriorated general fitness, and improved mental health. The sizes of the response shift effects on observed change were only small. Yet, accounting for the recalibration response shifts did change the estimate of true change in physical health from medium to large. The structural equation modeling approach was found to be useful in detecting response shift effects. The extent to which the procedure is guided by subjective decisions is discussed.     

Validity of utilities of patients with esophageal cancer

OBJECTIVES: The convergent validity between utility assessment methods was assessed. METHODS: Investigated were patients with esophageal cancer treated surgically with curative intent. Patients were interviewed in a period from 3 to 12 months after surgical resection. Patients evaluated their actual health and seven other states. Visual analogue scale (VAS) and standard gamble (SG) utilities were obtained for the health states in an interview. Patients also indicated whether or not they preferred death to living in a health state (worse than dead [WTD] preferences). RESULTS: Fifty patients completed the interview. Convergent validity was excellent at the aggregate and individual level. However, the relation between VAS and SG differed strongly across individuals. On a scale from 0 (dead) to 100 (perfect health), SG scores were lower for patients with WTD preferences (mean difference d = 35; p = .002); however, VAS scores did not vary by WTD preferences. CONCLUSIONS: In general, there is good agreement between VAS and SG measures, although patients disagree about how the VAS and SG are related. The standard gamble varied by WTD preferences, however, the VAS did not.     

Quality of life and the duration of treatment with vitamin K antagonists in patients with deep venous thrombosis

In clinical practice, decisions on the duration of treatment with vitamin K antagonists are usually based on the presence of persistent risk factors, the risk of bleeding and centre policy. Little is known about the influence of patients' experienced quality of life. The objectives of this study were: 1). to explore the course of quality of life in patients with venous thrombosis treated for 3 months versus patients treated for 6 months with vitamin K antagonists; 2). to investigate the factors that were associated with the duration of treatment with vitamin K antagonists. The study sample comprised patients participating in a multi-centre clinical trial. Quality of life was assessed at study entry, after 10-14 days, 3 and 6 months in 360 patients. Overall, no differences in quality of life were found between the 2 patient groups. An interaction effect between group and time was found for physical functioning. Regression analyses indicated that the presence of one or more permanent risk factors, duration of hospitalisation, mobility prior to deep-vein thrombosis and study centre were associated with the duration of treatment with vitamin K antagonists. Interestingly, quality of life was not associated with treatment duration. Since study centre was the most important factor associated with treatment duration, local policy appears to have a great influence on decisions regarding the duration of treatment with vitamin K antagonists.     

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. Conclusion 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.