Table 4 Secondary outcome measures continued: Psycho-social status

Psycho-social

Geriatric Depression Scale (GDS) 15-items [49]

The GDS is used to assess an older person's level of depression with simple yes/no response set [59], and the fifteen item screening test has been reported to be satisfactory [49].

Depression Anxiety and Stress Scale 21(DASS) [60]

21-item self-report measure of severity of depression, anxiety, and stress psychological symptoms. Overall Distress can be calculated by summing each of the sub-scale scores with possible scores ranging from 0-63, with higher scores indicating higher distress [48].

Scale of Psychological Wellbeing (SPWB) [47]

The SPWB measures well-being and psychological functioning includes six subscales: autonomy; environmental mastery; personal growth; positive relations with others; purpose in life; and self-acceptance [47]. Participants are required to rate agreement on a six point agreement scale, with higher scores indicating greater wellbeing.

Duke Social Support (DSS)[50]

The DSS is used to assess perceived adequacy and size of social support network on a 3 point scale with higher total scores reflecting higher levels of social support [50].

Quality of life

Life satisfaction Scale (LSS)[44]

This single item 7 point delighted-terrible rating scale provides a gestalt measure of life satisfaction, and can yield reliable and valid data [61].

Physical and Mental Health Summary Scales (SF36)^®

The Physical & Mental Health Summary Scales include eight generic health concepts, selected from 40 included in the Medical Outcomes Study (MOS), and MOS researchers selected and adapted questionnaire items and developed new measures for a 149-item Functioning and Well-Being Profile [62] the source for SF-36^® items.

Quality of Life Scales (QoLS)[46]

This 16 item 7 Likert type delighted-terrible self report scale measures satisfaction with five conceptual aspects of life notably material and physical wellbeing; relationships with other people, social, community and civic activities; personal development and fulfilment; and recreation [46].