Quality of Life General (QGEN^®) Summary

Quality of Life General (QGEN®) is a new survey published by JWRG that uses improved single-item-per-domain (SIPD) scales to measure eight of the most frequently measured health-related quality of life (HRQOL) domains, including: functioning (physical, role, and social) and feelings (pain, vitality, and mental health). QGEN items have been shown to improve Medical Outcomes Study (MOS) short-form (SF) items by increasing response category ranges for the four functioning domains by raising the “ceiling” by about 1.0 SD units by redefining it as “Easy to do” in place of the common “Not at all limited” category. QGEN new SIPD bipolar items with response categories directly measuring the opposite poles for each higher-order feeling domain, including: MH (psychological distress vs well-being) and VT (energetic vs. worn out). Advantages include improved overall item efficiency (information/item) and response categories that increase score range enough to significantly reduce ceiling effects. QGEN items have been shown to provide unbiased estimates of average scores for the profile of SF-36 multi-item scales measuring the same eight domains. QGEN items have also been shown to accurately estimate SF-36 physical (PCS) and mental (MCS) summary scores and the SF-6D health utility index. As with all MOS short forms, higher scores indicate better functioning and well-being. Specifically, profiles and summary scores are transformed to have mean=50 and SD=10 in a true probability sample representing 97% of the general US population surveyed by NORC in 2020. This standardization enables meaningful comparisons with more than three decades of population norms, published effect sizes, minimally important differences, and other published interpretation guidelines. One of the key advantages of QGEN is its efficiency. In comparison with SF-36 and comparable (e.g., PROMIS) multi-item short-forms measuring the same domains, US general population and clinical studies have shown that the eight-item QGEN reduces survey administration time by more than 75%, to about 1 minute for most respondents while increasing score range and domain representation. This makes it a convenient and efficient option for maintaining comparability with the metrics most widely in clinical and general population studies of QOL outcomes. JWRG’s objective is to increase the efficiency of single-item-per-domain (SIPD) health-related quality of life (QOL) enough to enable representation of essential QOL domains in surveys with severe respondent burden constraints while also providing more powerful screens for determining whether additional measurement is necessary. Quality of Life General (QGEN®) is a new survey developed by JWRG that measures eight health-related quality of life (HRQOL) domains, including functioning (physical, role, and social) and feelings (pain, vitality, and emotional well-being). The QGEN items improve Medical Outcomes Study (MOS) short-form (SF) items by increasing response category ranges for the three functioning domains and constructing items directly measuring the three higher-order feeling domains MH and VT factors. Results include improved item efficiency, response categories that increase score range and reduced ceiling effects.

JWRG’s objective is to increase the efficiency of single-item-per-domain (SIPD) health-related quality of life (QOL) enough to enable representation of essential QOL domains in surveys with severe respondent burden constraints.