Table 1.
Characteristics of included studies.
| Studies | Country (Ethnicity) | Mean age at baseline (SD) | Participant numbers | Female (%) | Event numbers | Maximum follow-up years | Hearing function evaluations | Instruments qualifying/quantifying cognitive status |
|---|---|---|---|---|---|---|---|---|
| Deal JA29 | US (White and Black) | 75.5 (3.0) | 1,889 | 52.7 | 229 | 9 | Pure-tone audiometry | 3MS score |
| Fritze T32 | Germany (NA) | ≥ 65 | 154,783 | NA | 14,602 | 6 | ICD-10 | ICD-10 |
| Gates GA31 | US (NA) | 72 (63–95)a | 1,662/1,026b | 60.2 | 41 | 6 | Pure-tone audiometry, SSI-ICM | MMSE score |
| Gates GA30 | US (NA) | 79.6 (5.2) | 274 | 62.8 | 21 | 2.2 (0.8–4)a | SSI-ICM | CASI score, DSM-IV, and NINCDS-ADRDA |
| Gurgel RK33 | US (NA) | 75.5 (6.9) | 4,463 | 60 | 574 | 5.8 (4.2)c | Self-report interview | 3MS score, DSM-III-R, and NINCDS-ADRDA |
| Hong T24 | Australia (NA) | 68.2 (7.9)d | 1,638d | 43.7d | NA | 10 | Pure-tone audiometry | MMSE blind |
| Karpa MJ9 | Australia (NA) | 66.6 (9.3) | 2,815 | 56.7 | NA | 9 | Pure-tone audiometry | MMSE score |
| Lin FR14 | US (Black, White and other) | 63.6 (12.8) | 639 | 43.7 | 58 | 11.9e | Pure-tone audiometry | DSM-III-R, and NINCDS-ADRDA |
| Lin FR20 | US (White and Black) | 77.4 (2.8)f | 1,626 | 52.1f | 609 | 6 | Pure-tone audiometry | 3MS score |
| Lin MY21 | US (Black excluded) | 76.1 (NA) | 5,345 | 100 | NA | 4.4 (NA)c | Pure-tone audiometry | 3MS score |
| Lyu J34 | South Korea (Asian) | 71.1 (4.9) | 1,759 | 52.6 | 501 | 6 | Self-report | Korean MMSE |
Abbreviations: 3MS = Modified Mini-Mental State Examination, CASI = Cognitive Abilities Screening Instrument, DSM = Diagnostic and Statistical Manual, ICD = International Classification of Diseases, MMSE = Mini-Mental State Examination, NA = not available, NINCDS-ADRDA = National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer’s Disease and Related Disorders Association, SD = standard deviation, SSI-ICM = Synthetic Sentence Identification with Ipsilateral Competing Message, UK = United Kingdom, US = United States. aMean (range), bperipheral hearing test/central hearing test, cmean (SD), ddata from hearing impairment cohort and controls, emedian, fdata from the whole cohort.