Defnyddiodd yr astudiaeth ddata’r GIG i gymharu faint mae pobl sydd wedi elwa ar welliannau arbed ynni cynllun Nyth yn defnyddio’r GIG â grŵp rheoli a oedd yn gymwys am welliannau ond a oedd yn aros iddynt gael eu cwblhau.
The study used NHS data to compare the health service use of people who had benefited from Nest home energy improvements and a control group who were eligible for improvements, but were still waiting for these to be completed.