Dr Rebbecca Lilley, senior research fellow in the injury prevention research unit, said the loss in work income was "mitigated" by public income transfers from the ACC, other benefits and New Zealand Superannuation.
This meant some badly affected workers lost 20% to 30% of their work income, but average total income losses were much less overall, amounting to between 3% and 7%.
ACC earnings-related compensation covered only 80% of a worker's wages, and for lower-income workers surviving from "day to day", lost work income was cumulative and hard to cope with.
"There's no room for complacency," Dr Lilley said.
This was the first time research had been undertaken on the financial impact of injuries on older New Zealand workers, and the study had just been published in the journal BMJ Open, researchers said.
Dr Lilley said the research she and her colleague, unit deputy director Gabrielle Davie, undertook had highlighted the importance of social welfare safety nets.
If those welfare and ACC supports were eroded, the impacts would be much greater, when workers needed "to be saving for their future retirement", she said.
The country's population was rapidly ageing, and 20% of over-65-year-olds receiving New Zealand Superannuation were working, the fourth highest rate of work participation beyond 65 years in the OECD.
Using Statistics NZ's integrated data infrastructure, the researchers identified a cohort of 617,722 workers aged 45 to 64, including more than 20,000 with substantial work or non-work injuries in 2009.
Researchers followed the cohort for three years, finding that their income fell, and
that the losses were greater among the injured.
In the third year, injured people received on average $2630 less than those in an uninjured comparison group, equivalent to a 7% income drop.
Although sometimes taken for granted, older workers were a "highly reliable and engaged workforce".
Given the rapidly ageing workforce and future employment shortages, it was vital that workplaces improved working conditions to encourage their workers to return to work more rapidly, Dr Lilley said.
