Adjusted for working days, output fell by 1.2 per cent from April 2014.
Working-day adjusted output grew in March by 0.9 per cent from March 2014, the revised data show.
The revision was caused by the benchmarking of the data to quarterly accounts.
Primary production refers to agriculture, hunting, forestry and fishing. Secondary production includes manufacturing and construction.
Services comprise trade, hotel and restaurant activities, transport and business activities, as well as real estate, renting and research services, financial intermediation and insurance, and public services.