ObjectiveTo assign clinical meanings to the Family Reported Outcome Measure (FROM-16) scores through the development of score bands using the anchor-based approach.Design and settingA cross-sectional online study recruited participants through UK-based patient support groups, research support platforms (HealthWise Wales, Autism Research Centre-Cambridge University database, Join Dementia Research) and through social service departments in Wales.ParticipantsFamily members/partners (aged ≥18 years) of patients with different health conditions.InterventionFamily members/partners of patients completed the FROM-16 questionnaire and a Global Question (GQ).Main outcome measureVarious FROM-16 band sets were devised as a result of mapping of mean, median and mode of the GQ scores to FROM-16 total score, and receiver operating characteristic-area under the curve cut-off values. The band set with the best agreement with GQ based on weighted kappa was selected.ResultsA total of 4413 family members/partners (male=1533, 34.7%; female=2858, 64.8%; Prefer not to say=16, 0.4%; other=6, 0.14%) of people with a health condition (male=1994, 45.2%; female=2400, 54.4%; Prefer not to say=12, 0.3%; other=7, 0.16%) completed the online survey: mean FROM-16 score=15.02 (range 0–32, SD=8.08), mean GQ score=2.32 (range 0–4, SD=1.08). The proposed FROM-16 score bandings are: 0–1=no effect on the quality of life of family member; 2–8=small effect on family member; 9–16=moderate effect on family member; 17–25=very large effect on family member; 26–32=extremely large effect on family member (weighted kappa=0.60).ConclusionThe FROM-16 score descriptor bands provide new information to clinicians about interpreting scores and score changes, allowing better-informed treatment decisions for patients and their families. The score banding of FROM-16, along with a short administration time, demonstrates its potential to support holistic clinical practice.