Use of the Houghton Scale to Classify Community and Household Walking Ability in People With Lower-Limb Amputation: Criterion-Related Validity.

Objective: To examine the criterion-related validity of using the self-reported Houghton Scale to classify community-dwelling people with lower-limb amputation according to the suggested score ranges for independent community (Houghton Scale score ≥9), household and limited community (Houghton Scale scores 6-8), and limited household (Houghton Scale score ≤5) walking ability categories as referenced to performance-based balance ability and walking speed criteria.

Design: Cross-sectional cohort study. Setting: Community-based wellness walking programs in 8 states in the Mid-Atlantic, Midwest, and Southeast regions of the U.S. Participants: Volunteers (N=180; 66.5% men, n=118; mean age, 55.5±16y) 7.1±13.1 years since amputation, with transtibial-level amputation in 47% (n=79) and amputation caused by vascular disease in 49.4% (n=89). Interventions: None. Main outcome measures: Self-reported data: Houghton Scale, Prosthetic Evaluation Questionnaire mobility subscale, and Activities-specific Balance Confidence (ABC) Scale. Clinical performance-based measures: balance ability assessed with 3 Berg Balance Scale (BBS) items and walking ability assessed with the timed Up and Go (TUG) test and 2-minute walk test (2MWT). The primary reference criteria were performance-based balance ability measured with the 3 BBS items and gait speed calculated from the 2MWT.

Results: On the Houghton Scale, 45.9% (78/170) of the participants scored ≥9, 30.6% (52/170) of the participants scored between 6 and 8, and 23.5% (40/170) of the participants scored ≤5. The Houghton Scale correlated with the Prosthetic Evaluation Questionnaire mobility subscale (r=.73), ABC Scale (r=.76), balance ability (r=.67), TUG test (r=-.67), and 2MWT (r=.73). The 3 Houghton Scale ability categories differed significantly from each other (P<.05) for all outcome measures: Prosthetic Evaluation Questionnaire mobility subscale, ABC Scale, balance ability, TUG test, and 2MWT.

Conclusions: The Houghton Scale demonstrated criterion-related validity by differentiating community-dwelling people with lower-limb amputation into community, limited community/household, and household ability categories that corresponded to performance-based balance and walking criteria. Average prosthetic walking speeds for each category compared with similar walking ability categories defined in other patient populations.