“…The following covariates were used in analyses: age, marital status (married/cohabiting [reference category], single, divorced/separated and widowed) [40], [41], educational attainment (university, secondary/vocational [reference category], primary or less) [42], [43], material deprivation level score [44], [45] which was based on three questions concerning how often the participants' household did not have enough money to buy food or clothes, or to pay bills such as housing, heating and electricity, with the possible answers “never”, “rarely”, “sometimes”, “often” or “all the time”, coded as 0–4. These items were summed and then categorised into three groups: low (reference category; scores of 0–1), intermediate (scores of 2–8) and high (scores of 9–12).…”