Sons were the most likely abusers at home, according to the preliminary results of the survey, the Asahi Shimbun reported yesterday.

The Ministry of Health, Labour and Welfare conducted the survey after a law aimed at preventing abuse of elderly people took effect in April last year.

The ministry contacted 47 prefectural governments and 1,829 municipal governments to investigate the extent of abuse of people 65 years or older.

More than 12,600 cases of elderly abuse were reported last year, almost all of them at home, according to the survey released late last week.

About 50 cases involved abuse inflicted by staff at nursing homes.

The national survey showed 80 per cent of the victims were women aged 80 or older.

The survey also showed about 40 per cent of the abused suffered from dementia.

Despite Japan's traditional respect for the aged, increasing life spans and lack of welfare support systems have put greater pressure on families caring for elderly parents and grandparents.

While sons were the top abusers in the reported cases at 37 per cent, husbands and daughters followed at 14 per cent each, and daughters-in-law were responsible for abuse in 10 per cent of the cases, according to the report.

The most common form of abuse was 'physical abuse', including slaps which accounted for 64 per cent of the cases.

'Psychological abuse', including abusive remarks, was cited in 36 per cent of the cases.

'Negligence of care', such as leaving the elderly for hours without meals, accounted for 29 per cent, while 'economic abuse', such as selling their properties without their consent, made up 27 per cent of the cases.

Multiple responses were allowed for the survey.

At nursing homes and other outside facilities, 80 per cent of the abusers were staff members of the facilities, and half of them were younger than 40 years old.

In some of the 53 confirmed cases, the abuse was committed by the facilities' managers.

Ms Ikuko Honma, who heads a non-profit citizens organisation aiming to improve the level of nursing-care homes, said the survey's figures likely understated the extent of the abuse, particularly at outside facilities.

Nearly 22 per cent of Japan's 127.8 million population are aged 65 or older, according to government data released this month. The percentage is expected to nearly double by 2055.

ASSOCIATED PRESS