Mortgage industry researcher Digital Finance Analytics has reported a fall in mortgage stress, thanks to lower interest rates.According to DFA, currently 21.7 per cent of households are in difficulty. It did not say what the level was previously but its previous research showed that 22.5 per cent of people aged 40 to 49 were in mortgage stress.DFA defines mild stress as households maintaining repayments but having to re-prioritise spending decisions, use credit cards for regular spending or refinance. Severe stress involves falling behind with debt payments, facing foreclosure or selling the house.DFA's report echoes the findings of a recent Bankwest Curtin Economics Centre survey, which found that stress levels had fallen in Western Australia.It found that the proportion of WA households with mortgages that are in the bottom two income quintiles and who pay more than 30 per cent in housing costs has fallen from 13 per cent in 2011/12 to around eight per cent today.DFA said the two groups most prone to mortgage stress were first-home buyers and older households. It estimates that 25 per cent of people aged 80 to 89 are in mortgage stress.DFA principal Martin North said: "Stress is not just the domain of the young. Proportionally, older households with loans are more likely to be stressed because incomes are squeezed."