The Bristol ADL scale is an informant-rated measure that covers 20 ADLs, both basic and instrumental. Items are rated on a four-point scale (from totally dependent to totally independent, with an additional “not applicable” option).
The BADLS was developed specifically for use in people with dementia, as existing scales were felt to be insensitive to change in this group, having been designed for healthy older adults or people with physical disabilities. Initially, 22 items were included based on the rationale that they appeared in at least two existing ADL measures. Caregivers of people with dementia completed the questionnaire by mail, including feedback on the relevance and importance of the items and response options. Some modifications were made to the scale, with the next version incorporating different response options. Two items on which participants scored at floor and ceiling respectively were removed, leading to the final 20-item version. Bucks and Haworth (2002) stated that the measure is regularly used in 58% of memory clinics in the United Kingdom, but that a revision was needed in order to increase sensitivity to mild cognitive impairment and to reflect changes in understanding of disability (particularly in light of the 2001 WHO framework) since the scale was developed. Bucks and Haworth (2002) also stated that studies evaluating a revised BADLS are underway, but no papers reporting these studies have been published to date (information correct as of 02.06.09).
The 22-item preliminary version of the BADLS had good test–retest reliability (r = 0.95, for kappa scores for individual items see Bucks et al., 1996), and evidence of its validity was found through correlations between the BADLS and MMSE scores (r = 0.55), and between BADLS and observed performance ratings (r = 65). The final 20-item version of the BADLS, completed by 50 caregivers of people with dementia (mixed diagnoses), found estimates of reliability and validity consistent with the previous version, with BADLS–MMSE scores correlating at 0.67. Principal components analysis identified a four-factor structure consisting of instrumental ADLs (7 items explaining 40.3% of variance), self care (6 items explaining 10.3% of variance), orientation (5 items explaining 7.5% of variance), and mobility (2 items explaining 7% of variance). Byrne et al. (2000) found that the BADLS was a good measure of change in ADL proficiency over time in people with Alzheimer’s disease (AD) receiving anticholinesterase inhibitors, as judged by its correlations with MMSE and ADAS-Cog scores, and sensitivity of 74% and specificity of 65% in detecting improvement/stability versus decline, in comparison with clinician-rated judgments.
A recent systematic review of 12 instrumental ADL scales for persons with dementia (Sikkes, de Lange-de Klerk, Pijnenburg, Scheltens and Uitdehaag, 2009) concluded that the BADLS was of “moderate quality,” the highest rating awarded in the review, which was given to only two measures, BADLS and the Disability Assessment for Dementia.
Wicklund et al. (2007) noted that the Bristol ADL scale is heavily weighted towards basic ADLs rather than instrumental ADLs, so this should be borne in mind when considering using it. Nonetheless, the BADLS has been used as a primary or secondary outcome measure in a number of clinical trials, including those of pharmaceutical and psychosocial interventions in people with dementia. Recent examples include open-label and controlled trials on the safety of aspirin (AD2000 Collaborative Group, 2008) and neuroleptic treatments (Ballard et al., 2008) in people with AD, a comparison of cholinesterase inhibitor and glutamate agonist treatment in moderate-severe AD (Jones et al., 2009), and RCTs of reminiscence therapy (Woods et al., 2009) and interpersonal psychotherapy (Burns et al., 2005) for people with Azheimer’s disease and other dementias. Bucks and Haworth (2002) have noted that completing the questionnaire may be in itself helpful for caregivers, as it can help them to understand the effects of dementia in real-life terms.