Improving caregiving competence, stress coping, and mental well-being in informal dementia carers

Table 2 Psychometric details of outcome measures

Instrument	Descriptions	Ref.
15-item geriatric depression scale	Validated and widely applied in older populations in community, acute and long-term care settings.	[35,36]
	Fifteen questions from the Long Form GDS which had the highest correlation with depressive symptoms in validation studies were selected for the Short Form GDS.
	Scores of 0-4 are considered normal; 5-8 indicate mild depression; 9-11 indicate moderate depression; and 12-15 indicate severe depression.
Self-mastery scale	Self-mastery is a perception that reflects one’s personal mastery or control over life outcomes	[26]
	Seven items are scored on a 4-point (agree-disagree format) scale with two items recoded in the opposite direction to produce scores ranging from 7 to 28.
	In the current study, Mastery score was calculated using a negative-oriented scale (i.e., response to positively phrased questions were reverse-coded). Thus, lower scores indicate higher self-mastery.
Role captivity scale	Three-items scale assesses degree of entrapment which carers perceive in their caregiving role.	[26]
	A 4-point Likert scale is used to document the extent to which carers may feel constrained in their caregiving role during the past week.
	Scores may range from 3 to 12, with higher scores indicating more role captivity.
Role overload scale	Four-item scale that reflects how carers may be overwhelmed as their time and energy level are being exhausted by the demands of caregiving.	[26]
	A 4-point Likert scale reports extent to which carers may feel overloaded in the past week.
	Scores may range from 4 to 16, with higher scores indicating more overload.
Caregiving competence scale	Four-item scale measures carers’ self-perception of his/her ability to carry out carer role properly.	[26]
	A 4-point Likert scale reports the level of competence.
12-item zarit burden interview	Covers multiple domains: financial difficulties, social life, physical and psychological health, and the relationship between the persons with dementia and the carer.	[14]
	A 5-point Likert scale assesses level of burden experienced by carers
	Total burden scores range from 0 to 60, with higher scores reflecting greater caregiver burden.
Coping inventory for stressful situations	48-item measure describes the manner in which an individual responds to stressful situations. It measures three forms of coping style: emotion-focused, task-oriented, avoidance-oriented	[28,29]
	For each coping strategy, respondents rate the usage frequency on a 5-point Likert scale ranging from 1 (not at all) to 5 (very much).

GDS: Geriatric depression scale.