Australian Journal of Physiotherapy 2005 Vol. 51 197

Activities-specific and Balance Confidence (ABC) Scale

Description

Commentary

The Activities-specific and Balance Confidence (ABC) Scaleis a questionnaire developed to measure an aspect of thepsychological impact of balance impairment and/or falls. Theunderlying construct being measured by the ABC scale isbased on the self efficacy theory reported by Tinetti et al(1990).

Target Time Cost Special population(s) taken training

required

Older people; 10-20 Nil Nopeople at risk minutesof falling

Instructions to the client and method of scoring The clientis asked to rate his or her confidence in performing each ofthe activities on a scale from 0 (no confidence) to 100%(complete confidence) without losing balance or becomingunsteady. An average percentage for each of the 16 items iscalculated. Well older people have been reported to score90–100% on the ABC scale (Myers et al 1998).

Sensitivity/specificity A cut-off score of 67% on the ABCresulted in 84% sensitivity and 87% specificity in correctlyclassifying fallers and non-fallers in a cross-sectional study ofolder people living in the community (Lajoie and Gallagher2004).

Reliability High retest reliability for the overall scale andmost of the individual items has been reported in samples ofcommunity dwelling older people (r = 0.92) (Powell andMyers 1995), and lower limb amputees (ICC = 0.91) (Miller,et al. 2003).

Validity The ABC scale differentiated older people whoreported avoiding activity because of fear of falling fromthose who did not (Myers et al 1996). Significantly lowerABC scores were associated with lower levels of mobility(Powell and Myers 1995) and falls (Lajoie and Gallagher2004). The ABC scale correlated significantly with a range ofbalance and mobility scores in samples of older people withmild balance impairments, and clients who had fractured theirhips (Cho et al 2004, Lajoie and Gallagher 2004, Whiteheadet al 2003). The ABC scale was responsive to change with abalance exercise program in older people living in retirementvillages, and in a sample of osteoarthritic clients followinghip or knee replacement surgery (Myers et al 1998). Hipfracture clients who fell in the four months following surgeryhad significantly lower ABC scores at baseline compared tothose who did not fall (Whitehead et al 2003). Significantcorrelations were reported between the ABC scale and theDizziness Handicap Inventory in clients attending avestibular clinic (Whitney et al 1999).

Keith HillNational Ageing Research Institute, Melbourne

A major innovation in the measurement of psychologicalsequelae of falls occurred in 1990 with the development ofthe Falls Efficacy Scale (FES) by Tinetti et al (1990). TheFES introduced the concepts that falls efficacy is acontinuum, not a dichotomous factor, and that it is situation-specific, that is, it varies depending upon the activity andenvironment. A limitation of the 10 item FES was that theactivities being considered were of low level challenge to thebalance system. Three modifications of the original FES havebeen developed to include more challenging activities, withthe aim of earlier identification of problems with fallsefficacy. These were the ABC scale (Powell and Myers 1995),

the Modified Falls Efficacy Scale (Hill et al 1996), and theSwedish version of the Falls Efficacy Scale [FES(S)](Hellstrom and Lindmark 1999).

The ABC is a useful clinical tool for a range of client groups.However, administration of the scale does require the client tohave reasonably intact cognition. In particular the client mustunderstand that what is being assessed is confidence in doingthe activity, not ease with which the activity can beperformed.

Keith HillNational Ageing Research Institute, Melbourne

Clinimetrics

References

Cho B et al (2004): J Amer Geriatr Soc 52: 1168–1173.

Hellstrom K and Lindmark B (1999): Clin Rehabil 13: 509–517.

Hill K et al (1996): Arch Phys Med Rehabil 77: 1025–1029.

Lajoie Y and Gallagher SP (2004): Arch Gerontol Geriatr 38:11–26.

Miller WC et al (2003) Arch Phys Med Rehabil 84: 656–661.

Myers A et al (1996): J Gerontol 51A: M37–43.

Myers A et al (1998): J Gerontol 53A: M287–294.

Powell L and Myers A (1995): J Gerontol 50A: M28–34.

Tinetti M et al (1990): J Gerontol 45: P239–243.

Whitehead C et al (2003): Clin Rehabil 17: 899–906.

Whitney SL et al (1999): J Vestib Res 9: 253–259.