Short IQCODE as a screening tool for MCI and dementia: preliminary results

Perroco, Tíbor Rilho; Damin, Antonio Eduardo; Frota, Norberto A.; Silva, Mari-Nilva M.; Rossi, Viviane; Nitrini, Ricardo; Bottino, Cássio M.C.

doi:10.1590/S1980-57642009DN20400012

Abstract

Reaching a diagnosis may be difficult in the initial stages of dementia, especially in low educated individuals, when informant reports may be useful. Objectives: To compare the sensitivity and specificity of the IQCODE against cognitive tests applied in clinical practice and to evaluate the possible cut-off points in Brazil. Methods: Individuals without dementia (CDR=0; N=5), with Mild Cognitive Impairment (MCI) (CDR=0.5; N=15) and demented (CDR³1; N=29) were evaluated using the Short IQCODE, a 16-item questionnaire applied to an informant, and on standard cognitive and functional scales. Diagnosis was reached by a consensus team with expertise in dementia, according to DSM-IV criteria, which was blind to the IQCODE results. Results: IQCODE scores were positively correlated to the CDR (r=0.65, p<0.001) and negatively correlated with years of schooling (r= -0.33, p=0.021). IQCODE scores were positively correlated with CDR controlled by age and education (r=0.61, p<0.001). Linear regression showed that age was associated with the IQCODE (p=0.016) whereas education was not associated (p=0.078). IQCODE means according to the CDR classification were: CDR 0-3.37; CDR 0.5-3.75; CDR 1-4.32; CDR 2-4.61; CDR 3-5.00. The area under the ROC curve for dementia vs. controls was 0.869 (p<0.001), MCI vs. controls, 0.821 (p<0.001); and according to the groups classified by the CDR was: CDR 0.5 vs. CDR 1=0.649 (p=0.089), CDR 1 vs. CDR 2=0.779 (p=0.009), and CDR 2 vs. CDR 3=0.979 (p=0.023). Conclusions: These preliminary findings suggest that the short IQCODE can be used for the screening of MCI and dementia in Brazil.

Key words:
dementia; diagnosis; cognitive test; functional scales; screening tests; informant report.

Resumo

O diagnóstico pode ser difícil em estágios iniciais de demência, especialmente em população de baixa escolaridade, quando os relatos de informantes podem ser úteis. Objetivo: Comparar a sensibilidade e especificidade do IQCODE com outros testes e diagnóstico clinico, assim como identificar os possíveis pontos de corte no Brasil. Métodos: Indivíduos sem demência (CDR=0; N=5), com comprometimento cognitivo leve (MCI) (CDR=0,5; N=15) e dementados (CDR³1; N=29) foram avaliados usando o IQCODE reduzido, um questionário de 16 itens aplicado ao informante, e escalas cognitivas e funcionais padrões. Diagnóstico final foi fornecido por consenso de especialistas, com experiência em demência, de acordo com os critérios do DSM-IV, e cegos quanto ao resultado do IQCODE. Resultados: IQCODE tem uma correlação positiva com o CDR (r=0.65, p<0.001) e negativa com anos de escolaridade (r= -0.33, p=0.021). IQCODE mantêm correlação positiva com o CDR quando controlado por idade e escolaridade (r=0.61, p<0.001). Na regressão linear a idade continuou a afetar o resultado do IQCODE (p=0.016) enquanto a escolaridade não (p=0.078). Médias do IQCODE de acordo com a classificação do CDR: CDR 0-3.37; CDR 0.5-3.75; CDR 1-4.32; CDR 2-4.61; CDR 3-5.00. A área sob a curva ROC para demência vs. controles foi 0.869 (p<0.001), MCI vs. controles, 0.821 (p<0.001) e de acordo com os CDR foi: CDR 0.5 vs. CDR 1=0.649 (p=0.089), CDR 1 vs. CDR 2=0.779 (p=0.009) e CDR 2 vs. CDR 3 =0.979 (p=0.023). Conclusão: Esses achados preliminares sugerem que o IQCODE Curto pode ser usado como instrumento de triagem para MCI e demência no Brasil.

Key words:
demência; diagnóstico; teste cognitivo; escalas funcionais; testes de rastreio; relatos de informante.

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References

¹
Bottino CMC, Azevedo D, Tatsch M, et al. Estimate of Dementia prevalence in a community sample from São Paulo, Brazil. Dement Geriatr Cogn Disord 2008; 26:291-299.
²
Carr DB, Gray S, Baty J, Morris JC. The value of informant versus individual´s complaints of memory impairment in early dementia. Neurology 2000;55:1724-1726.
³
Mackinnon A, Mulligan R. Combining cognitive testing and informant report to increase accuracy in screening for dementia. Am J Psychiatry 1998;155:1529-1535.
⁴
Bustamante, Sonia E, Zevallos, et al. Instrumentos combinados na avaliação de demência em idosos: resultados preliminares. Arq Neuropsiquiatr 2003;61:601-606.
⁵
Jorm AF. The Informant questionnaire on cognitive decline in the elderly (IQCODE): a review. Int Psychogeriatr 2004;16: 275-293.
⁶
Teng EL, Cultural and educational factors in the diagnosis of dementia. Alzheimer Dis Assoc Disord 2002;16(suppl. 2):S77-S79.
⁷
Galvin JE, Roe CM, Xiong C, Morris JC. Validity and reliability of the AD8 informant interview in dementia. Neurology 2006;67:1942-1948.
⁸
Jorm AF, Jacomb PA. The informant questionnaire on cognitive decline in the elderly (IQCODE): Socio-demographic correlates, reliability, validity and some Norms. Psychol Med 1989;19:1015-1022.
⁹
Jorm AF, Korten AE. Assessment of cognitive decline in the elderly by informant interview. Br J Psychiatry 1988;152:209-213.
¹⁰
Isella V, Villa ML. Frattola L, Appollonio I. Screening cognitive decline in dementia: preliminary data on Italian version of the IQCODE. Neurol Sci 2002;23:S79-S80.
¹¹
Senanarong V, Assavisaraporn S, Sivasiriyanonds N, et al. The IQCODE: an alternative screening test for dementia for low educated Thai. J Med Assoc Thai 2001;84:648-655.
¹²
Jorm AF, Christensen H, Henderson AS, Jacomb PA, Korten AE, Mackinnon A. Informant ratings of cognitive decline of elderly people: relationship to longitudinal change on cognitive tests. Age Ageing 1996;25:125-129.
¹³
de Jonghe JF, Schmand B, Ooms ME, Ribbe MW. Abbreviated form of the Informant Questionnaire on cognitive decline in the elderly. Tijdschr Gerontol Geriatr 1997;28:224-229.
¹⁴
Morales JM, Gonzalez-Montalvo JL, Bermejo F, Del Ser T. The screening of mild dementia with a shortened Spanish version of the "Informant Questionnaire on Cognitive Decline in the Elderly". Alzheimer Dis Assoc Disord 1995;9:105-111.
¹⁵
Petersen RC, Smith E, Warring SC, Ivnik RJ, Tangalos E, Kokmen E. Mild cognitive impairment: clinical characterization and outcome. Arch Neurol 1999;56:303-308.
¹⁶
Brucki SMD, Nitrini R, Caramelli P, Bertolucci PHF, Okamoto IH. Sugestões para o uso do mini-exame do estado mental no Brasil. Arq Neuropsiquiatr 2003;61:777-781.
¹⁷
Bottino CMC, Almeida OP, Tamai S, Forlenza OV, Scalco MZ, Carvalho IAM. Entrevista estruturada para diagnóstico de transtornos mentais em idosos-CAMDEX The Cambridge examination for mental disorders of the elderly. Versão brasileira, traduzida e adaptada com autorização dos editores, Cambridge University Press, São Paulo, 1999.
¹⁸
Cummings JL, Mega M, Gray K, Rosenberg-Thompson S, Carusi DA, Gornbein J. The Neuropsychiatric Inventory: comprehensive assessment of psychopathology in dementia. Neurology 1994;44:2308-2314.
¹⁹
Nitrini R, Caramelli P, Bottino CM, Damasceno BP, Brucki SM, Anghinah R; Academia Brasileira de Neurologia. [Diagnosis of Alzheimer's disease in Brazil: cognitive and functional evaluation. Recommendations of the Scientific Department of Cognitive Neurology and Aging of the Brazilian Academy of Neurology]. Arq Neuropsiquiatr 2005;63:720-727.
²⁰
American Psychiatric Association. Diagnostic and statistical manual of mental disorders: DSM-IV, 4th edition,1994.
²¹
Altmann D. ROC Curves, (editors). Practical statistics for medical research. London: Chapman & Hall; 1992.
²²
Altmann D, (editor). Logistic Regression. Practical statistics for medical research. London: Chapman & Hall; 1992.
²³
Morales JM, Gonzalez-Montalvo JL, Bermejo F, Del Ser T. Screening of dementia in community-dwelling elderly through informant report. Int J Geriatr Psychiatry 1997;12: 808-816.
²⁴
Jorm AF. A short form of the Informant questionnaire on cognitive decline in the elderly (IQCODE): development and cross-validation. Psychol Med 1994;24: 145-153.
²⁵
Del-Ser T, Morales JM, Barquero MS, Canton R, Bermejo F. Application of a spanish version of the "Informant Questionnaire on Cognitive Decline in the Elderly" in the clinical assessment of dementia. Alzheimer Dis Assoc Disord 1998; 11:3-8.
²⁶
Harwood DM, Hope T, Jacoby R. Cognitive impairment in medical inpatients. I: Screening for dementia--is history better than mental state? Age Ageing. 1997 ;26:31-35.
²⁷
Isella V, Villa L, Russo A, Regazzoni R, Ferrarese C, Appollonio IM. Discriminative and predictive power of an informant report in mild cognitive impairment. J Neurol Neurosurg Psychiatry 2006;77:166-171.
²⁸
Fegyveres RA, Formigoni AP, Porto CS, et al. Applicability of cognitive questionnaire in the elderly and proxy. Dement Neuropsychol 2008;2:228-232.
²⁹
Fuh JL, Teng EL, Lin KN, et al. The informant questionnaire on cognitive decline in the elderly (IQCODE) as a screening tool for dementia for a predominantly illiterate Chinese population. Neurology 1995;45:92-96.

Publication Dates

Publication in this collection
Oct-Dec 2008

History

Received
29 Oct 2008
Accepted
15 Nov 2008

This is an open-access article distributed under the terms of the Creative Commons Attribution License

[1] ¹
Bottino CMC, Azevedo D, Tatsch M, et al. Estimate of Dementia prevalence in a community sample from São Paulo, Brazil. Dement Geriatr Cogn Disord 2008; 26:291-299.

[2] ²
Carr DB, Gray S, Baty J, Morris JC. The value of informant versus individual´s complaints of memory impairment in early dementia. Neurology 2000;55:1724-1726.

[3] ³
Mackinnon A, Mulligan R. Combining cognitive testing and informant report to increase accuracy in screening for dementia. Am J Psychiatry 1998;155:1529-1535.

[4] ⁴
Bustamante, Sonia E, Zevallos, et al. Instrumentos combinados na avaliação de demência em idosos: resultados preliminares. Arq Neuropsiquiatr 2003;61:601-606.

[5] ⁵
Jorm AF. The Informant questionnaire on cognitive decline in the elderly (IQCODE): a review. Int Psychogeriatr 2004;16: 275-293.

[6] ⁶
Teng EL, Cultural and educational factors in the diagnosis of dementia. Alzheimer Dis Assoc Disord 2002;16(suppl. 2):S77-S79.

[7] ⁷
Galvin JE, Roe CM, Xiong C, Morris JC. Validity and reliability of the AD8 informant interview in dementia. Neurology 2006;67:1942-1948.

[8] ⁸
Jorm AF, Jacomb PA. The informant questionnaire on cognitive decline in the elderly (IQCODE): Socio-demographic correlates, reliability, validity and some Norms. Psychol Med 1989;19:1015-1022.

[9] ⁹
Jorm AF, Korten AE. Assessment of cognitive decline in the elderly by informant interview. Br J Psychiatry 1988;152:209-213.

[10] ¹⁰
Isella V, Villa ML. Frattola L, Appollonio I. Screening cognitive decline in dementia: preliminary data on Italian version of the IQCODE. Neurol Sci 2002;23:S79-S80.

[11] ¹¹
Senanarong V, Assavisaraporn S, Sivasiriyanonds N, et al. The IQCODE: an alternative screening test for dementia for low educated Thai. J Med Assoc Thai 2001;84:648-655.

[12] ¹²
Jorm AF, Christensen H, Henderson AS, Jacomb PA, Korten AE, Mackinnon A. Informant ratings of cognitive decline of elderly people: relationship to longitudinal change on cognitive tests. Age Ageing 1996;25:125-129.

[13] ¹³
de Jonghe JF, Schmand B, Ooms ME, Ribbe MW. Abbreviated form of the Informant Questionnaire on cognitive decline in the elderly. Tijdschr Gerontol Geriatr 1997;28:224-229.

[14] ¹⁴
Morales JM, Gonzalez-Montalvo JL, Bermejo F, Del Ser T. The screening of mild dementia with a shortened Spanish version of the "Informant Questionnaire on Cognitive Decline in the Elderly". Alzheimer Dis Assoc Disord 1995;9:105-111.

[15] ¹⁵
Petersen RC, Smith E, Warring SC, Ivnik RJ, Tangalos E, Kokmen E. Mild cognitive impairment: clinical characterization and outcome. Arch Neurol 1999;56:303-308.

[16] ¹⁶
Brucki SMD, Nitrini R, Caramelli P, Bertolucci PHF, Okamoto IH. Sugestões para o uso do mini-exame do estado mental no Brasil. Arq Neuropsiquiatr 2003;61:777-781.

[17] ¹⁷
Bottino CMC, Almeida OP, Tamai S, Forlenza OV, Scalco MZ, Carvalho IAM. Entrevista estruturada para diagnóstico de transtornos mentais em idosos-CAMDEX The Cambridge examination for mental disorders of the elderly. Versão brasileira, traduzida e adaptada com autorização dos editores, Cambridge University Press, São Paulo, 1999.

[18] ¹⁸
Cummings JL, Mega M, Gray K, Rosenberg-Thompson S, Carusi DA, Gornbein J. The Neuropsychiatric Inventory: comprehensive assessment of psychopathology in dementia. Neurology 1994;44:2308-2314.

[19] ¹⁹
Nitrini R, Caramelli P, Bottino CM, Damasceno BP, Brucki SM, Anghinah R; Academia Brasileira de Neurologia. [Diagnosis of Alzheimer's disease in Brazil: cognitive and functional evaluation. Recommendations of the Scientific Department of Cognitive Neurology and Aging of the Brazilian Academy of Neurology]. Arq Neuropsiquiatr 2005;63:720-727.

[20] ²⁰
American Psychiatric Association. Diagnostic and statistical manual of mental disorders: DSM-IV, 4th edition,1994.

[21] ²¹
Altmann D. ROC Curves, (editors). Practical statistics for medical research. London: Chapman & Hall; 1992.

[22] ²²
Altmann D, (editor). Logistic Regression. Practical statistics for medical research. London: Chapman & Hall; 1992.

[23] ²³
Morales JM, Gonzalez-Montalvo JL, Bermejo F, Del Ser T. Screening of dementia in community-dwelling elderly through informant report. Int J Geriatr Psychiatry 1997;12: 808-816.

[24] ²⁴
Jorm AF. A short form of the Informant questionnaire on cognitive decline in the elderly (IQCODE): development and cross-validation. Psychol Med 1994;24: 145-153.

[25] ²⁵
Del-Ser T, Morales JM, Barquero MS, Canton R, Bermejo F. Application of a spanish version of the "Informant Questionnaire on Cognitive Decline in the Elderly" in the clinical assessment of dementia. Alzheimer Dis Assoc Disord 1998; 11:3-8.

[26] ²⁶
Harwood DM, Hope T, Jacoby R. Cognitive impairment in medical inpatients. I: Screening for dementia--is history better than mental state? Age Ageing. 1997 ;26:31-35.

[27] ²⁷
Isella V, Villa L, Russo A, Regazzoni R, Ferrarese C, Appollonio IM. Discriminative and predictive power of an informant report in mild cognitive impairment. J Neurol Neurosurg Psychiatry 2006;77:166-171.

[28] ²⁸
Fegyveres RA, Formigoni AP, Porto CS, et al. Applicability of cognitive questionnaire in the elderly and proxy. Dement Neuropsychol 2008;2:228-232.

[29] ²⁹
Fuh JL, Teng EL, Lin KN, et al. The informant questionnaire on cognitive decline in the elderly (IQCODE) as a screening tool for dementia for a predominantly illiterate Chinese population. Neurology 1995;45:92-96.

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