Improved Quality of Life General (QGEN®) Short Form Survey Published by JWRG

The shortest possible, comprehensive patient reported outcome (PRO) survey, QGEN-8, uses a single newly constructed item to measure each of the eight SF-36 generic health-related quality of life (HRQOL) domains more broadly, over a wider range of levels with directly comparable scores.

The shortest possible patient reported outcome (PRO) survey enabled by an improved single-item-per-domain (SIPD) scale for each of the eight most frequently measured HRQOL outcomes has been published in Medical Care Read here. For all four Medical Outcomes Study (MOS) short form functioning domains, new QGEN items increase response category ranges and reduce “ceiling” effects by redefining the highest activity level as “Easy to do” in place of legacy “Not at all limited” categories. For bipolar feeling (ill- vs well-being) domains, a new SIPD item was constructed to directly measure both of the opposite poles of each higher-order domain (factor) previously requiring multiple items. For example: one item for Mental Health (psychological distress vs well-being) and one item for Vitality (feeling energetic vs. worn out). The practical advantages of QGEN item improvements demonstrated in general and chronically ill US and international populations, include:

  • Improved overall item efficiency (simply more information/item;
  • Reduced survey respondent burden (by 75%, < 1 minute for most adults);
  • Increased range of measurement significantly reducing ceiling effects (i.e., the percentages for whom improved outcomes cannot be measured);
  • Substantial convergent validity with other measures of the same domains and discriminant validity for different domains in comparison with the best legacy profiles and summary (PCS and MCS) measures; and
  • U.S. population T-score (Mean=50, SD=10) transformations directly comparable to the most widely used measures of the same domains.

As with all short forms based on the MOS model, higher scores indicate better health-related functioning and well-being. Norm-based scoring algorithms are based on true probability samples representing 97% of the general US population surveyed by NORC. Thus, with standardized norm-based scoring, QGEN items provide unbiased estimates of average scores observed for the profile of MOS multi-item measures of the same eight domains as well as accurate estimates of SF-36 physical (PCS) and mental (MCS) component summary and SF-6D health utility scores in general and chronically ill populations. This standardization enables meaningful comparisons of outcomes with more than three decades of published population norms, treatment effect sizes, minimally important differences, and other proven interpretation guidelines.

To assure QGEN-8 availability for population and clinical outcomes research, it is available in multiple languages from the non-profit Mapi Research Trust (MRT) at (htps://eprovide.mapi-trust.org).


Licensing JWRG's QGEN