Dk. Heyland et al., FREQUENCY AND METHODOLOGIC RIGOR OF QUALITY-OF-LIFE ASSESSMENTS IN THE CRITICAL CARE LITERATURE, Critical care medicine, 26(3), 1998, pp. 591-598
Objectives: To present a framework for describing/measuring quality of
life (QOL) and health-related quality of life (HRQL), and to assess t
he frequency and methodologic rigor of QOL studies in the adult critic
al care literature. Data Sources: Computerized bibliographic search of
published research, manual search of key intensive care unit (ICU) jo
urnals, and citation review of relevant articles. Study Selection: We
manually searched Critical Care Medicine American Journal of Respirato
ry and Critical Care Medicine, and Intensive Care Medicine for the per
iod January 1992 to July 1995 to assess the frequency of published QOL
studies. Combined with a computerized bibliographic search, we found
64 studies that met our criteria that reported on patient-related outc
omes (other than mortality) after hospital discharge. Data Extraction:
We abstracted data on the nature of each study, the instruments used
to measure QOL, and the methodologic rigor of the QOL assessments. We
evaluated each study using criteria we developed to assess the validit
y of HRQL measurements. Measurements and Main Results: in our manual s
earch, we found 1,073 articles relevant to the practice of adult criti
cal care. Of these, 19(1.7%)/1073 included QOL measurements. Combined
with our comprehensive search strategy, we found 64 papers that evalua
ted QOL in ICU patients. These papers dealt primarily with issues of:
prognosis(32 [50%]), resource allocation (23 [36%]), and clinical pred
iction (9 [14%]). We found no randomized trials that included post-ICU
QOL as an outcome. With respect to the validity of the HRQL assessmen
ts, 63/64 (98%) studies evaluated aspects at patients' lives that we c
onsidered important. Thirty-three (52%) studies were limited in scope
to specific aspects of HRQL, and 31 (48%) studies covered broad areas
of HRQL. In these 64 studies, there were 108 different instruments use
d. The reliability and validity of the instruments used were reported
in 7 (6%) and 15 (14%) cases, respectively. For 81 (75%) instruments,
the investigators either explained the results or used informative, qu
alitative descriptors whose interpretation was self-evident. Overall,
three (5%) of the included studies met all four methodologic criteria
to assess the validity of HRQL assessments. Conclusions: QOL assessmen
ts occur infrequently in the ICU literature and are of limited methodo
logic quality. More studies using valid and reliable instruments are n
ecessary to document the long-term QOL of critically ill patients, esp
ecially those at risk of a ''poor'' outcome.