“…The four-item LS scale (range: 4–20) has been modified by Eric Allardt for Nordic welfare studies ( Allardt, 1976 ). It has been used in several patient ( Koivumaa-Honkanen et al, 2008 , Koivumaa-Honkanen et al, 1996 , Kuivasaari-Pirinen et al, 2014 , Pakarinen et al, 2016 , Salakari et al, 2016 ) and general population samples ( Koivumaa-Honkanen et al, 2011 , Koivumaa-Honkanen et al, 2000 , Rauma et al, 2014 , Rissanen et al, 2011 ). It has a strong long-term predictive ability for various long-term health outcomes ( Koivumaa-Honkanen et al, 2000 , Koivumaa-Honkanen et al, 2004 , Rauma et al, 2014 ) and a strong concurrent association with and long-term predictive power to depression both in general ( Koivumaa-Honkanen et al, 2004 ) and patients population samples ( Koivumaa-Honkanen et al, 2008 , Rissanen et al, 2011 ).…”