The purpose of cognitive screening tests such as the SMT is to estimate the likelihood of genuine cognitive impairment, inferred from the relationship between patients’ scores to reference norms.
The digital SMT represents the only known digital screener of the likely driving competence of older people with MCI or early dementia. It is administered on various tablet devices using a handheld stylus pen. The digital SMT replicates the original exactly in terms of size and task requirements
The results will be available through a user account. This will include a pictorial representation of the patients performance, providing both qualitative and quantitative information.
In its original format, the SMT was a timed pencil and paper screening test of the cognitive domains of attention, visuoconstructional skills, and the executive functions of planning and foresight, all of which are required for safe driving.
A study has examined the performance characteristics of the SMT, and estimated its criterion-referenced validity, using a group of 115 older drivers with MCI or early dementia recruited from an Outpatient Memory Clinic in South Australia (SA). The gold standard used for driving competence was a standardised on-road driving assessment administered by authorised and accredited driving instructors employed by Transport SA. They were unaware of the cognitive status of participants. The SMT was able to be standardized, and found to be simple, brief to administer and score, and safe and acceptable to the target group. Scores (time for completion in seconds, and number of errors) were not influenced by age, gender, educational attainment, or country of birth. The SMT only measured those skills required for safe driving; speed for attention (SMT time), and visuoconstructional skills, and the executive functions of planning and foresight (SMT errors). In this sample the SMT time and error scores predicted on-road driving competence with high sensitivity, specificity, and overall accuracy (Snellgrove, 2005, 2006).
Subsequent independent studies have supported the criterion-referenced validity, sensitivity, specificity, and overall accuracy of the pencil and paper version of the SMT (Carr et al., 2011; Barco et al., 2014; Ott et al., 2013,). The SMT has been recommended for the screening of likely on-road competence of older drivers with early cognitive impairment, and has been well accepted among researchers, clinicians and patients for its ease of use and short administration time (American Geriatrics Society, 2016; Antimisiaria & Morton, 2017; ANZSGM Position Statement, 2009; Bolz & Galvin, 2015; Canadian Stroke Best Practice Recommendations, 2019; Chun, 2020; Cochrane Database Systematic Reviews, 2013; Ham’s Primary Care Geriatrics, 2021; Mwarni et al., 2013; Platz, 2021; RACP & AFRM Position Statement, 2014).
Some pencil and paper cognitive assessment techniques can suffer from human error and bias, despite standardised administration. Computer based technologies are increasingly common in neuropsychology with benefits of standardisation of administration, immediate scoring, accurate recording, and secure data storage (Bracken et al., 2018). For example, and specific to older adults with MCI or early dementia, the Digital Clock Drawing Test (Muller et al., 2017), and Digital Trail Making Test (Dahmen et al., 2017) have been shown to measure the same aspects of cognition as their original pencil and paper versions.
The digital SMT represents the only known digital screener of the likely driving competence of older people with MCI or early dementia. It is administered on various tablet devices using a handheld stylus pen. The digital SMT replicates the original exactly in terms of size (11 cm2, 14 cm2 for the SMT), and task requirements. The results will be available through a user account and users will also receive an email with a link to results. This will include a pictorial representation of the patients performance, providing both qualitative and quantitative information.
