The Role of Generic and Disease-specific Measures of Physical and Role Functioning in Assessing Patient Outcomes

Cancer symptom response as an oncology clinical trial end point

Introduction

A critical challenge in oncology is interpreting clinical trial results to inform clinical decision making. Clinical trials typically focus on overall survival (OS) and progression-free survival (PFS) as primary endpoints, which do not reflect early signs of meaningful patient benefit or harm. Cancer symptom response (CSR) can provide information about early treatment response, and studies show that CSR predicts long-term health outcomes.

Areas covered

CSR requires careful consideration of its measurement and interpretation to facilitate integration into clinical practice. We describe considerations for the evaluation, analysis, and interpretation of CSR in clinical trials. To illustrate the potential clinical value of CSR, we performed a retrospective analysis of a three-arm randomized cooperative-group clinical trial.

Expert commentary

Evaluation of CSR provides a meaningful assessment of early cancer treatment effects. It can act as an early signal of disease progression and death and thus can identify which patients with stable disease will have a more favorable prognosis. Future research will include development of methods for more accurate assessment of CSR, reduction of the number of symptoms used as signals for disease progression or survival by tumor type, and statistical methods that effectively correct for missing data and informative censoring.

Sensitivity of alternative measures of functioning and wellbeing for adults with sickle cell disease: comparison of PROMIS® to ASCQ-Me℠

BACKGROUND

Sickle Cell Disease (SCD) causes profound suffering and decrements in daily functioning. Demand is growing for valid and reliable measures to systematically document these effects, particularly in adults. The Adult Sickle Cell Quality of Life Measurement System, ASCQ-Me℠, was developed for this purpose. ASCQ-Me℠ is one of four measurement systems housed within the Person-Centered Assessment Resource (PCAR), funded by the National Institutes of Health, to support clinical research. To help users select the best of these measures for adults with SCD, we evaluated and compared two PCAR systems: one designed to be "universally applicable" (the Patient-Reported Outcome Measurement Information System, PROMIS®) and one designed specifically for SCD (ASCQ-Me℠).

METHODS

Respondents to PROMIS and ASCQ-Me questions were 490 adults with SCD from seven geographically-disbursed clinics within the US. Data were collected for six ASCQ-Me measures (Emotional Impact, Sleep Impact, Social Impact, Stiffness Impact, Pain Impact, SCD Pain Episode Frequency and Severity) and ten PROMIS measures (Pain Impact, Pain Behavior, Physical Functioning, Anxiety, Depression, Fatigue, Satisfaction with Discretionary Social Activities, Satisfaction with Social Roles, Sleep Disturbance, and Sleep-Related Impairment). Statistical analyses, including analysis of variance and multiple linear regression, were conducted to determine the sensitivity of measures to SCD severity. SCD severity was assessed via a checklist of associated treatments and conditions.

RESULTS

For those with the most severe SCD, PROMIS scores showed worse health compared to the general population for nine of ten health domains: the magnitude of the difference ranged 0.5 to 1.1 standard deviation units. The PROMIS domains most severely affected were Physical Functioning and Pain (Impact and Behavior). Significant differences by tertile of the SCD-MHC were shown for most PROMIS short forms and all ASCQ-Me short and fixed forms. In most models, ASCQ-Me measures explained statistically significant unique variance in SCD-MHC scores complementary to that explained by corresponding PROMIS measures.

CONCLUSIONS

Study results supported the validity of both PROMIS and ASCQ-Me measures for use in adults with SCD. Compared to comparable PROMIS scores, most ASCQ-Me scores were better predictors of SCD disease severity, as measured by a medical history checklist. The clinical implications of these results require further investigation.

How to measure the impact of premenstrual symptoms? Development and validation of the German PMS-Impact Questionnaire

With 75% of women of reproductive age affected, premenstrual symptoms are very common, ranging from emotional and cognitive to physical symptoms. Premenstrual Syndrome and Premenstrual Dysphoric Disorder can lead to substantial functional interference and psychological distress comparable to that of dysthymic disorders. The assessment of this impact is required as a part of the diagnostic procedure in the DSM-5. In the absence of a specific measure, the authors developed the PMS-Impact Questionnaire. A sample of 101 women reporting severe premenstrual complaints was assessed with the twenty-two items in the questionnaire during their premenstrual phase in an ongoing intervention study at the Philipps-University Marburg from August 2013 until January 2015. An exploratory factor analysis revealed a two-factor solution (labeled Psychological Impact and Functional Impact) with 18 items. A Cronbach's alpha of 0.90 for Psychological Impact and of 0.90 for Functional Impact indicated good reliability. Convergent construct validity was demonstrated by moderate to high correlations with the Pain Disability Index. Low correlations with the Big Five Inventory-10 indicated good divergent validity. The PMS-Impact Questionnaire was found to be a valid, reliable, and an economic measure to assess the impact of premenstrual symptoms. In future research, cross validations and confirmatory factor analyses should be conducted.

Validation of the English version of the Kidney Disease Quality of Life questionnaire (KDQOL-36) in haemodialysis patients in Singapore

BACKGROUND

To validate a widely used health outcomes instrument for patients with chronic kidney disease and on dialysis, the Kidney Disease Quality of Life questionnaire (KDQOL-36), in English-speaking haemodialysis patients in Singapore.

METHODS

This study is a secondary data analysis using the KDQOL-SF (version 1.3) data collected from a cross-sectional survey of haemodialysis patients in Singapore. Cronbach's α was used to test internal consistency reliability. Multi-item scales were assessed using item-to-scale correlation and factor analysis. Both confirmatory and exploratory factor analyses were performed separately for generic and disease-targeted scales. Construct validity was assessed by correlation between disease-targeted and generic scales. Criterion validity was assessed by correlation of the physical component summary (PCS-12) and mental component summary (MCS-12) from KDQOL-36 with the corresponding PCS-36 and MCS-36 from the KDQOL-SF.

RESULTS

Three hundred ninety-four patients who completed the interviews in English [male 55.8 %, mean age (SD) 52.4 (11.7) years] were involved. Kidney disease scales exhibited desirable internal consistency (Cronbach's α 0.822-0.906) and item-to-scale correlation (range 0.763-0.903), and a three-factor model fit the data well [comparative fit index (CFI) 0.934, root mean square error of approximation (RMSEA) 0.085]. For the generic Short Form 12 Health Survey (SF-12) items, a two-factor model (physical and mental) showed poor overall fit, but a three-factor structure (role, physical and mental functions) achieved good model fit (CFI 0.999, RMSEA 0.027). Correlation between disease-targeted and generic scales was weak to moderate (range 0.286-0.418). Correlation between SF-12 and SF-36 was 0.750 for PCS and 0.797 for MCS.

CONCLUSION

The English version of the KDQOL-36 appears to be reliable and valid to measure quality of life for haemodialysis patients in Singapore.

Meta-analyses of the effect of false-positive mammograms on generic and specific psychosocial outcomes

OBJECTIVES

While a previous meta-analysis found that false-positive mammography results affect women's likelihood of returning for screening, effects on well being have yet to be meta-analyzed. We investigated whether the effects of false-positive mammograms on women's well-being are limited to outcomes specific to breast cancer.

METHODS

We searched MEDLINE for studies of the psychosocial effects of false-positive results of routine screening mammography. We pooled effect sizes using random effects meta-analysis.

RESULTS

Across 17 studies (n=20781), receiving a false-positive mammogram the result was associated with differences in all eight breast-cancer-specific outcomes that we examined. These included greater anxiety and distress about breast cancer as well as more frequent breast self-exams and higher perceived effectiveness of screening mammography. False positives were associated with only one of six generic outcomes (i.e. generalized anxiety), and this effect size was small.

CONCLUSIONS

False-positive mammograms influenced women's well-being, but the effects were limited to breast-cancer-specific outcomes. Researchers should include disease-specific measures in future studies of the consequences of false-positive mammograms.

Measurement invariance of the kidney disease and quality of life instrument (KDQOL-SF) across veterans and non-veterans

BACKGROUND

Studies have demonstrated that perceived health-related quality of life (HRQOL) of patients receiving hemodialysis is significantly impaired. Since HRQOL outcome data are often used to compare groups to determine health care effectiveness it is imperative that measures of HRQOL are valid. However, valid HRQOL comparisons between groups can only be made if instrument invariance is demonstrated. The Kidney Disease Quality of Life-Short Form (KDQOL-SF) is a widely used HRQOL measure for patients with chronic kidney disease (CKD) however, it has not been validated in the Veteran population. Therefore, the purpose of this study was to examine the measurement invariance of the KDQOL-SF across Veterans and non-Veterans with CKD.

METHODS

Data for this study were from two large prospective observational studies of patients receiving hemodialysis: 1) Veteran End-Stage Renal Disease Study (VETERAN) (N = 314) and 2) Dialysis Outcomes and Practice Patterns Study (DOPPS) (N = 3,300). Health-related quality of life was measured with the KDQOL-SF, which consists of the SF-36 and the Kidney Disease Component Summary (KDCS). Single-group confirmatory factor analysis was used to evaluate the goodness-of-fit of the hypothesized measurement model for responses to the subscales of the KDCS and SF-36 instruments when analyzed together; and given acceptable goodness-of-fit in each group, multigroup CFA was used to compare the structure of this factor model in the two samples. Pattern of factor loadings (configural invariance), the magnitude of factor loadings (metric invariance), and the magnitude of item intercepts (scalar invariance) were assessed as well as the degree to which factors have the same variances, covariances, and means across groups (structural invariance).

RESULTS

CFA demonstrated that the hypothesized two-factor model (KDCS and SF-36) fit the data of both the Veteran and DOPPS samples well, supporting configural invariance. Multigroup CFA results concerning metric and scalar invariance suggested partial strict invariance for the SF-36, but only weak invariance for the KDCS. Structural invariance was not supported.

CONCLUSIONS

Results suggest that Veterans may interpret the KDQOL-SF differently than non-Veterans. Further evaluation of measurement invariance of the KDQOL-SF between Veterans and non-Veterans is needed using large, randomly selected samples before comparisons between these two groups using the KDQOL-SF can be done reliably.

Validity, reliability, and responsiveness of the Kansas City Cardiomyopathy Questionnaire in anemic heart failure patients

BACKGROUND

While generic health status measures quantify the impact of all patients' diseases on their health-related quality of life, disease specific measures focus on only one of the many conditions that a patient may have. If a patient has two diseases with similar clinical manifestations, they may respond differently to a disease-specific instrument if one of their conditions improves while the other worsens or remains stable, thus undermining the instruments in that patient population. We sought empirical evidence of the reliability and validity (including responsiveness) of the Kansas City Cardiomyopathy Questionnaire (KCCQ), a disease-specific measure for heart failure (HF), among HF patients with and without anemia, a condition that has similar symptoms to HF.

METHODS

This work used a prospective cohort study of 811 HF outpatients from 58 U.S. centers with a baseline assessment of anemia of whom 698 were followed for 3 months with serial health status measures.

RESULTS

Among participants, 268 (33%) were anemic. The construct validity of the KCCQ was supported by showing similar correlations with the New York Heart Association (NYHA) classification in patients with and without anemia (P value for interaction = 0.38). The internal consistency (Cronbach's alpha = 0.92 and 0.93 for anemic and non-anemic patients, respectively) and test-retest reliability (mean 3-month change scores in stable patients = -2.8 [SD = 1.4] and -0.5 [SD = 0.8], P = 0.14) were similar. Estimates of responsiveness were also similar.

CONCLUSION

This study provides empirical evidence that the psychometric properties of the KCCQ are similar in patients with or without anemia, a potentially confounding clinical condition in patients with heart failure.

Development and validation of the Tangible, Informational, and Emotional Social Support Survey

BACKGROUND

Social support is an important resource for chronic disease management. However, it is not routinely assessed in the context of caring for patients with cardiovascular disease or as part of the cardiovascular rehabilitation process. The objective was to develop a survey designed to measure the types of social support that are necessary in cardiovascular disease prevention and management.

METHODS

Items were derived based on qualitative interviews with 63 patients regarding their perception of the most helpful types of social support in health behavior modification. Test-retest reliability was determined among 43 new patients. Factor analysis was conducted to determine the structural domains of the survey. The survey was then validated against the Medical Outcomes Study Social Support Survey in 130 patients.

RESULTS

The survey used, which was called Tangible, Informational, and Emotional Social Support Survey, contains 16 items that explore tangible, informational, and emotional social support. Cronbach coefficient was .80. Exploratory factor analysis revealed a 4-factor solution, which accounted for 54% of the total variance. Patients who were married had higher scores (P < .05), compared with those who were not and scores on Tangible, Informational, and Emotional Social Support Survey correlated with the scores on the Medical Outcomes Study Social Support Survey (r = 0.82).

CONCLUSIONS

Tangible, Informational, and Emotional Social Support Survey is a patient-derived, reliable, and valid social support survey. It can be used to capture salient aspects of social support that may facilitate health behavior modification in cardiovascular disease patients.

Dissemination of Methods and Results From the Veterans Health Study

The Veterans Health Study (VHS) followed a cohort of patients receiving ambulatory care in the Veterans Affairs healthcare system for up to 5 years. One of the principal aims of this study was to develop a library of methodologies including general and disease-specific health outcome questionnaires for use in monitoring the quality of healthcare and for research purposes. The cornerstone for this work is the Veterans RAND 36 and 12 Item Health Surveys (VR-36 and VR-12), a general measure developed in the VHS for measuring the physical and psychologic well-being of the patient. A comprehensive set of disease-specific assessments has also been developed as part of this study for the purposes of monitoring specific chronic conditions more commonly seen in routine ambulatory care settings. Since 1996, more than 2 million questionnaires have been administered in the VA for quality monitoring purposes, using the VR-36 and VR-12. Research studies that have used these batteries span randomized clinical trials in the VA cooperative studies program and clinical effectiveness research. Health assessments using VHS batteries are being disseminated for widespread use outside the VA. Chief among the assessments used is the VR-12, which has recently been included in the 2006 Health Plan Employer Data and Information Set (HEDIS) as part of the Medicare Health Outcomes Survey for monitoring the Medicare Advantage Program. The methods and batteries developed in the VHS are in the public domain and provide a framework for future patient monitoring using standard measures of health.