Evaluation of smoking-specific and generic quality of life measures in current and former smokers in Germany and the United States

Impact of tobacco and/or nicotine products on health and functioning: a scoping review and findings from the preparatory phase of the development of a new self-report measure

BACKGROUND

Measuring self-reported experience of health and functioning is important for understanding the changes in the health status of individuals switching from cigarettes to less harmful tobacco and/or nicotine products (TNP) or reduced-risk products (RRP) and for supporting tobacco harm reduction strategies.

METHODS

This paper presents insights from three research activities from the preparatory phase of the development of a new self-report health and functioning measure. A scoping literature review was conducted to identify the positive and negative impact of TNP use on health and functioning. Focus groups (n = 29) on risk perception and individual interviews (n = 40) on perceived dependence in people who use TNPs were reanalyzed in the context of health and functioning, and expert opinion was gathered from five key opinion leaders and five technical consultants.

RESULTS

Triangulating the findings of the review of 97 articles, qualitative input from people who use TNPs, and expert feedback helped generate a preliminary conceptual framework including health and functioning and conceptually-related domains impacted by TNP use. Domains related to the future health and functioning measurement model include physical health signs and symptoms, general physical appearance, functioning (physical, sexual, cognitive, emotional, and social), and general health perceptions.

CONCLUSIONS

This preliminary conceptual framework can inform future research on development and validation of new measures for assessment of overall health and functioning impact of TNPs from the consumers' perspective.

Assisted reproductive technology treatments and quality of life: a longitudinal study among subfertile women and men

PURPOSE

Quality of life (QoL) may represent a comprehensive indicator for the assessment of the psychological impact of complex clinical conditions, such as infertility. Infertile women have a worse QoL compared to both infertile men and non-infertile controls. However, the initial phases of infertility treatments have been frequently investigated using cross-sectional study designs. This prospective longitudinal study aimed at assessing the health-related QoL change across different phases of assisted reproductive technology (ART) treatments in subfertile women and men.

METHODS

Eighty-five subfertile women and men undergoing ART cycles were assessed at the beginning of the ovarian stimulation, during oocyte retrieval before discharging, and around 14 days after the embryo transfer. QoL was assessed through the Short Form 36.

RESULTS

Irrespective of the cause of infertility, work status, and age, QoL levels decreased from the first to the third assessment, and women scored significantly lower than men to each QoL indicator. Additionally, a higher number of previous ART failures had a negative impact on QoL, irrespective of gender and the phase of treatment. ART outcome marginally affected women's QoL across time.

CONCLUSION

Infertile women have a worse QoL throughout all phases of ARTs compared to men, and this difference increases in infertile patients with more than one previous ART failure.

Standardizing disease-specific quality of life measures across multiple chronic conditions: development and initial evaluation of the QOL Disease Impact Scale (QDIS®)

BACKGROUND

To document the development and evaluation of the Quality of life Disease Impact Scale (QDIS®), a measure that standardizes item content and scoring across chronic conditions and provides a summary, norm-based QOL impact score for each disease.

METHODS

A bank of 49 disease impact items was constructed from previously-used descriptions of health impact to represent ten frequently-measured quality of life (QOL) content areas and operational definitions successfully utilized in generic QOL surveys. In contrast to health in general, all items were administered with attribution to a specific disease (osteoarthritis, rheumatoid arthritis, angina, myocardial infarction, congestive heart failure, chronic kidney disease (CKD), diabetes, asthma, or COPD). Responses from 5418 adults were analyzed as five disease groups: arthritis, cardiovascular, CKD, diabetes, and respiratory. Unidimensionality, item parameter and scale-level invariance, reliability, validity and responsiveness to change during 9-month follow-up were evaluated by disease group and for all groups combined using multi-group confirmatory factor analysis (MGCFA), item response theory (IRT) and analysis of variance methods. QDIS was normed in an independent chronically ill US population sample (N = 4120).

RESULTS

MGCFA confirmed a 1-factor model, justifying a summary score estimated using equal parameters for each item across disease groups. In support of standardized IRT-based scoring, correlations were very high between disease-specific and standardized IRT item slopes (r = 0.88-0.96), thresholds (r = 0.93-0.99) and person-level scores (r ≥ 0.99). Internal consistency, test-retest and person-level IRT reliability were consistently satisfactory across groups. In support of interpreting QDIS as a disease-specific measure, in comparison with generic measures, QDIS consistently discriminated markedly better across disease severity levels, correlated higher with other disease-specific measures in cross-sectional tests, and was more responsive in comparisons of groups with better, same or worse evaluations of disease-specific outcomes at the 9-month follow-up.

CONCLUSIONS

Standardization of content and scoring across diseases was shown to be justified psychometrically and enabled the first summary measure of disease-specific QOL impact normed in the chronically ill population. This disease-specific approach substantially improves discriminant validity and responsiveness over generic measures and provides a basis for better understanding the relative QOL impact of multiple chronic conditions in research and clinical practice.

The Validity of Disease-specific Quality of Life Attributions Among Adults with Multiple Chronic Conditions

BACKGROUND

A crucial assumption underlying all disease-specific quality of life (QOL) measures, that patients can validly differentiate a specific disease in the presence of multiple chronic conditions, has not been tested using multiple methods. Our objective was to evaluate the convergent and discriminant validity of QOL attributions to specific diseases among adults with multiple chronic conditions (MCC).

METHODS

Adults age 18 and older (N=4,480) sampled from eight pre-identified condition groups (asthma, COPD, angina/MI with angina, congestive heart failure, diabetes, chronic kidney disease, osteoarthritis, rheumatoid arthritis) completed an Internet survey. Comorbid conditions were determined using a 35-condition checklist. Product-moment correlations were analyzed separately by pre-identified condition group using the multitrait-multimethod of construct validation, where traits were defined by 9-26 conditions and each condition was measured by two methods: disease severity rating and Disease-specific Quality of Life Impact Scale (QDIS) global rating. A third method (symptom or clinical marker) was available for the eight pre-identified conditions. Convergent validity was supported when correlations among different methods of measuring the same condition (trait) were substantial (r≥0.40). Discriminant validity was supported when correlations between the same and different methods of measuring different conditions were significantly lower than corresponding convergent correlations.

RESULTS

In support of convergent validity, 22 of 24 convergent correlations were substantial (r=0.38-0.84, median=0.53). In support of discriminant validity, 833 of 924 tests (90.2%) yielded significantly higher convergent than discriminant correlations across the eight pre-identified conditions. Exceptions to this pattern of results were most often observed for comorbid conditions within the same clinical area.

CONCLUSIONS

Collectively, convergent and discriminant test results support the construct validity of disease-specific QOL impact attributions across MCC within the eight pre-identified conditions. Noteworthy exceptions should be considered when interpreting some specific QOL impact attributions and warrant further study. Pursuit of a summary disease-specific QOL impact score standardized across MCC is recommended.

Preliminary Evaluation of a New German Translated Tobacco Quality of Life Impact Tool to Discriminate Between Healthy Current and Former Smokers and to Explore the Effect of Switching Smokers to a Reduced Toxicant Prototype Cigarette

BACKGROUND

Assessment of health-related quality of life (HRQoL) is well established in clinical research, but ceiling effects in validated tools might prevent detection of changes in well respondents. Tobacco Quality of Life Impact Tool (TQOLITv1) uses conceptual and psychometric advances to enhance detection of HRQoL changes.

METHODS

In a 6-month, forced-switch study, the German TQOLITv1 was assessed in healthy adult (age 23-55 years) current and matched former-smokers. At baseline, smokers were switched to reduced toxicant prototype (RTP) or conventional cigarette for 6 months. TQOLITv1 responses were collected at baseline, 3 and 6 months from current smokers whilst former smokers completed it at the latter two time points. TQOLITv1 includes SF-36v2 and new smoking-specific, physical and general-health measures.

RESULTS

Reliability at baseline was good (Cronbach's coefficient alpha > 0.70) for all measures. The baseline percentage with the best possible score (ceiling effect) for former and current smokers was substantially better for the new physical function than SF-36 physical function measure (35% vs. 59% at ceiling, respectively). New smoking-specific measures discriminated current from former smokers better than general health measures. Smoking-specific symptoms (r = 0.73) were more stable from baseline to 6 months than other measures (r = 0.38-0.54) particularly more than the SF-36 mental component score (r = 0.24). Although both product smoking groups worsened in most HRQoL measures, changes in general and smoking-specific HRQoL impact measures favored RTP smokers.

CONCLUSIONS

The German TQOLITv1 is sufficiently reliable and valid to assess HRQoL and may be more useful than SF-36v2 in evaluation of interventions in well smoking populations including those consuming RTPs.