A systematic review finds limited data on measurement properties of instruments measuring outcomes in adult intensive care unit survivors.

BACKGROUND AND OBJECTIVE: There is a growing number of studies evaluating the physical, cognitive, mental health, and health-related quality of life (HRQOL) outcomes of adults surviving critical illness. However, there is little consensus on the most appropriate instruments to measure these outcomes. To inform the development of such consensus, we conducted a systematic review of the performance characteristics of instruments measuring physical, cognitive, mental health, and HRQOL outcomes in adult intensive care unit (ICU) survivors. METHODS: We searched PubMed, Embase, PsycInfo, Cumulative Index of Nursing and Allied Health Literature, and The Cochrane Library in March 2015. We also conducted manual searches of reference lists of eligible studies and relevant review articles. Two people independently selected studies, completed data abstraction, and assessed the quality of eligible studies using the COnsensus-based Standards for the selection of health Measurement Instruments (COSMIN) initiative checklist. RESULTS: We identified 20 studies which explicitly evaluated measurement properties for 21 different instruments assessing outcomes in ICU survivors. Eleven of the instruments assessed quality of life, with few instruments assessing other domains. Of the nine measurement properties evaluated on the COSMIN checklist, six were assessed in <10% of the evaluations. Overall quality of eligible studies was generally poor to fair based on the COSMIN checklist. CONCLUSIONS: Although an increasing number of studies measure physical, cognitive, mental health, and HRQOL outcomes in adult ICU survivors, data on the measurement properties of such instruments are sparse and generally of poor to fair quality. Empirical analyses evaluating the performance of instruments in adult ICU survivors are needed to advance research in this field.

Updated systematic review identifies substantial number of retention strategies: using more strategies retains more study participants.

BACKGROUND AND OBJECTIVE: The retention of participants in studies is important for the validity of research. We updated our prior systematic review (2005) to assess retention strategies for in-person follow-up in health care studies. METHODS: We searched PubMed, Cumulative Index of Nursing and Allied Health Literature, Cochrane Controlled Trials Register, Cochrane Methodology Register, and Embase (August 2013) for English-language reports of studies that described retention strategies for in-person follow-up in health care studies. We abstracted each retention strategy, and two authors independently classified each retention strategy with one of the themes developed in our prior review. RESULTS: We identified 88 studies (67 newly identified studies), six of which were designed to compare retention strategies, whereas the remainder described retention strategies and retention rates. There were 985 strategies abstracted from the descriptive studies (617 from new studies), with a median (interquartile range) number of strategies per study of 10 (7 to 17) and a median (interquartile range) number of themes per study of 6 (4 to 7). Financial incentives were used in 47 (57%) of the descriptive studies. We classified 28% of the strategies under the theme of "contact and scheduling methods," with 83% of the identified studies using at least one strategy within this theme. The number of strategies used was positively correlated with retention rate (P = 0.027), but the number of themes was not associated with retention rate (P = 0.469). CONCLUSION: The number of studies describing retention strategies has substantially increased since our prior review. However, the lack of comparative studies and the heterogeneity in the types of strategies, participant population and study designs, prohibits synthesis to determine the types of cohort retention strategies that were most effective. However, using a larger number of retention strategies, across five or six different themes, appears to retain more study participants.