Researchers led by Dr. Karen Glaser of King's College London analyzed data from an annual survey of more than 5,000 British households from 1991 to 2003.

Glaser said parents with health problems are 75 percent more likely to be helped than those without health problems, and for every extra year of a parent's age, he or she is 9 percent more likely to receive help from children not living at the same address.

Curiously, divorced parents get more help from children than if they are widowed, but both groups receive more help than if they still have a partner, Glaser said. Parents with more children receive more support; but stepchildren provide less support.

In 1988, 34 percent of British parents 61 to 69 received regular or frequent help from their children, but by 2001-2002 the total had risen to 43 percent.

Forty-four percent of the children said they provide transportation, 32 assisted with shopping, 25 percent helped with house repairs, 17 percent cooked meals and 16 percent helped with bill-paying.