Alzheimer’s Disease Assessment Scale - Cognitive Subscale (ADAS-Cog)

Portuguese version

Guerreiro, M., Fonseca, S., Barreto, J., & Garcia, C. (2008). Escala de Avaliação da Doença de Alzheimer (Alzheimer’s Disease Assessment Scale [ADAS]). In Alexandre de Mendonça, Manuela Guerreiro e Grupo de Estudos de Envelhecimento Cerebral e Demência (Eds.), Escalas e Testes na Demência (2.ª ed.; pp. 41-68) [Scales and Tests in Dementia, 2nd ed.]. Novartis.

Original version

Mohs, R. C., Rosen, W. G., Davis, K. L. (1983). The Alzheimer’s Disease Assessment Scale: An instrument for assessing treatment efficacy. Psychopharmacology Bulletin, 19, 448-450.

Theoretical background

The ADAS-Cog is a brief battery developed to assess cognitive performance in AD patients. The ADAS-Cog was also used as an outcome measure in clinical trials for AD to index the global level of cognitive functioning in response to therapies or drugs. The ADAS-Cog was developed according to the core characteristics of cognitive decline in AD and it is divided in two formal evaluation parts: the first is a brief interview that aims to assess several spontaneous language features (as fluency in speech, naming, comprehension and quality of speech); the second is a battery of tests that aim to assess multiple cognitive domains.

Description

Assessment Domain: Cognitive performance.

Type of instrument: Paper-and-pencil test, including oral and performance tasks.

Administration: Individual, 15-20 minutes.

Population: ≥ 50 years old (Adults and elderly).

Dimensions

The ADAS-Cog assesses five cognitive domains: memory, language, praxis, constructive ability and orientation.

Studies

In Portugal, the ADAS-Cog was translated, adapted and transculturally validated by Guerreiro and colleagues (2008). The validation study of the Portuguese version of the ADAS-Cog used a control group from which preliminary cut-off values by age and level of education (including illiterate individuals) were defined (Guerreiro et al., 2008). Recently, Nogueira and colleagues updated these normative data for the Portuguese population (Nogueira et al., 2018a) which expanded the knowledge about this instrument and the achievement of more accurate and reliable clinical use of the ADAS-Cog in Portugal or within the Portuguese speaking communities living abroad. Nogueira and colleagues also proceeded with a clinical validation for Mild Cognitive Impairment (MCI) and Alzheimer’s Disease (AD; Nogueira et al., 2018b). The results of the clinical validation show the excellent diagnostic accuracy of the ADAS-Cog total scores for dementia, and specifically, its good discriminative power for AD.

Future research

Ongoing studies has been contemplating the increment in the diagnostic accuracy parameters with the addition of a delayed recall subtask to the original ADAS-Cog. Future studies will consider the clinical validation of this scale in other clinical conditions within neurodegeneration spectrum.

Funding

The research studies of the ADAS-Cog were supported by the project granted to Sandra Freitas from Portuguese Foundation for Science and Technology (FCT, Fundação para a Ciência e a Tecnologia) [IF/FCT/01325/2015].

Contacts

Joana Nogueira (joananogueira.f@gmail.com)

Sandra Freitas (sandrafreitas0209@gmail.com)

References

1. Guerreiro, M., Fonseca, S., Barreto, J., & Garcia, C. (2008). Escala de Avaliação da Doença de Alzheimer (Alzheimer Disease Assessment Scale [ADAS]). In Alexandre de Mendonça, Manuela Guerreiro e Grupo de Estudos de Envelhecimento Cerebral e Demência (Eds.), Escalas e Testes na Demência (2.ª ed.; pp. 41-68) [Scales and Tests in Dementia]. Novartis.
2. Nogueira, J., Afonso, A., Freixo, A., Duro, D., Guerreiro, M., Almeida, J., Freitas, S., & Santana, I. (2016). “Validação Clínica da Escala da Escala de Avaliação da Doença de Alzheimer - Subescala Cognitiva (ADAS-Cog) para a população portuguesa” [Clinical Validation of the Alzheimer's Disease Assessment Scale - Cognitive Subscale (ADAS-Cog) for the Portuguese population]. 30th meeting of the “Grupo de Estudos de Envelhecimento Cerebral”.
3. Nogueira, J., Freitas, S., Duro, D., Almeida, J., & Santana, I. (2018b). Validation study of the Alzheimer’s Disease Assessment Scale – Cognitive subscale (ADAS-Cog) for the Portuguese patients with Mild Cognitive Impairment and Alzheimer’s Disease. The Clinical Neuropsychologist. https://doi.org/10.1080/13854046.2018.1454511
4. Nogueira, J., Freitas, S., Duro, D., Santiago, B., & Santana, I. (2017). “ADAS-Cog: Estudos atuais para a população Portuguesa” [ADAS-Cog: Current studies for the Portuguese population]. 31st meeting of the “Grupo de Estudos de Envelhecimento Cerebral”, Lisbon, Portugal.
5. Nogueira, J., Freitas, S., Duro, D., Santiago, B., & Santana, I. (2017). "Escala de Avaliação da Doença de Alzheimer - subescala cognitiva: Estudos recentes para a população portuguesa" [Alzheimer's Disease Assessment Scale - cognitive subscale: Recent studies for the Portuguese population]. Sociedade Portuguesa de Neurologia.
6. Nogueira, J., Freitas, S., Duro, D., Tábuas-Pereira, M., Guerreiro, M., Almeida, J. & Santana, I. (2018a). Alzheimer’s Disease Assessment Scale - Cognitive Subscale (ADAS-Cog): Normative Data for the Portuguese Population. Acta Médica Portuguesa, 31(2):94-100. https://doi.org/10.20344/amp.8859
7. Nogueira, J., Freitas, S., Duro, D., Tábuas-Pereira, M., Guerreiro, M., Almeida, J., & Santana, I. (2017). ADAS-Cog: Estudo Normativo para a população Portuguesa." [ADAS-Cog: Normative Study for the Portuguese population] 31st meeting of the “Grupo de Estudos de Envelhecimento Cerebral”.