Minimal important differences for fatigue patient reported outcome measures—a systematic review

Abstract

BackgroundFatigue is the most frequent symptom reported by patients with chronic illnesses. As a subjective experience, fatigue is commonly assessed with patient-reported outcome measures (PROMs). Currently, there are more than 40 generic and disease-specific PROMs for assessing fatigue in use today. The interpretation of changes in PROM scores may be enhanced by estimates of the so-called minimal important difference (MID). MIDs are not fixed attributes of PROMs but rather vary in relation to estimation method, clinical and demographic characteristics of the study group, etc. The purpose of this paper is to compile published MIDs for fatigue PROMs, spanning diagnostic/patient groups and estimation methods, and to provide information relevant for appraising their appropriateness for use in specific clinical trials and in monitoring fatigue in defined patient groups in routine clinical practice.MethodsA systematic search of three databases (Scopus, CINAHL and Cochrane) for studies published between January 2000 to April 2015 using fatigue and variations of the term MID, e.g. MCID, MIC, etc. Two authors screened search hits and extracted data independently. Data regarding MIDs, anchors used and study designs were compiled in tables.ResultsIncluded studies (n = 41) reported 60 studies or substudies estimating MID for 28 fatigue scales, subscales or single item measures in a variety of diagnostic groups and study designs. All studies used anchor-based methods, 21/60 measures also included distribution-based methods and 17/60 used triangulation of methods. Both similarities and dissimilarities were seen within the MIDs.ConclusionsMagnitudes of published MIDs for fatigue PROMs vary considerably. Information about the derivation of fatigue MIDs is needed to evaluate their applicability and suitability for use in clinical practice and research.

Quality-of-Life Outcomes From a Randomized Clinical Trial Comparing Antimetabolites for Intermediate, Posterior, and Panuveitis

“…However, literature regarding the vitality domain specifically has shown that the MCID can vary widely amongst health states and is generally set at a 5 point difference in scores. 44,45 So, while statistically significant, our results may not reflect a clinically meaningful decrease in the patient’s vitality.…”

Fatigue is a relevant outcome in patients with myasthenia gravis

“…For example, the group‐level MID of 5.3 points means that this is the minimal difference between treatment groups that would be clinically significant. A direct comparison cannot be drawn because they are different measures, but for context a T‐score MID range of 3.0–5.0 was reported for PROMIS Fatigue‐7 . Because of the small group of patients who were “a little better,” this value is exploratory, and we recommend future studies to establish MID cut‐points for other interventions.…”

A prospective study of fatigue trajectories among in‐centre haemodialysis patients

“…Non-white ethnicity was associated with a 2.95 lower initial fatigue severity and a reduction in fatigue severity of 1.60 points each year. In addition, a one-point increase in haemoglobin was predictive of a small, but not clinically meaningful (Nordin et al, 2016), increase in fatigue severity of .02 each year (B = À0.05, p = .050, 95% CI À0.10, À0.00008). In addition, a one-point increase in haemoglobin was predictive of a small, but not clinically meaningful (Nordin et al, 2016), increase in fatigue severity of .02 each year (B = À0.05, p = .050, 95% CI À0.10, À0.00008).…”

“…In the final model, including all the predictor variables (N = 14), only ethnicity was a significant predictor of the initial level of fatigue severity (B = À2.95, p = .024, 95% CI À5.51 to À0.40) and change in fatigue severity (B = 1.36, p = .009, 95% CI 0.35 to 2.36). These coefficients represent clinically significant changes in fatigue severity on the CFQ, particularly taking into consideration the additive impact of ethnicity over time (Nordin et al, 2016). These coefficients represent clinically significant changes in fatigue severity on the CFQ, particularly taking into consideration the additive impact of ethnicity over time (Nordin et al, 2016).…”