Psychometric properties of Hope Scales: A systematic review.

INTRODUCTION: Hope is recognised as an important factor in health, illness, and well-being. Many scales to measure hope have been developed and used in various disciplines, yet, their psychometric properties have not been systematically reviewed.

AIM: To systematically review the psychometric properties of hope scales.

DESIGN: Systematic review.

METHODS: Four electronic databases were searched followed by a hand search. The data were extracted and qualitatively evaluated by the COSMIN checklist, an instrument designed as a quality rating tool for systematic reviews of psychometric properties.

RESULTS: From 1271 retrieved abstracts, 68 papers met the inclusion criteria. The most used scale was the Snyder Hope Scale (46%) followed by the Herth Hope Index (16%). All other scales (n = 16) were evaluated in less than 10% of the papers. Structural validity (91%), internal consistency (88%), and hypothesis testing (74%) were the most reported properties. Reliability (34%), cross-cultural validity (34%), content validity (25%), and criterion validity (15%) were reported in less than 50% of the papers. Only two (3%) studies reported responsiveness, and none reported measurement error. Less than 35% of the validation studies achieved excellent or good quality for any of the measurement properties.

CONCLUSION: The results show that no robust and valid scale exists for measuring hope. It highlights important gaps in psychometric properties of hope scales. Despite more than 40 years of research and development of hope scales, the currently available scales do not meet the standards of psychometric evaluation. This calls for efforts to improve the quality of hope scales.