Table 1.

Overview measurements

	Instrument	Form	T0 – baseline	T1 – 6 months	T2 – 12 months
Individual with suspected cognitive impairment
GPs’ MCI or dementia diagnosis	1. GP asked to indicate dementia (and MCI) diagnoses of all study participants on a list				X
	2. Extraction dementia (and MCI) diagnoses from medical records
Reference standard MCI or dementia diagnosis	CAMCOG [17]	Interview	X		X
Quality of life	QoL-AD [18] & EQ5D	Interview	X	X	X
Mood	MH5 (SF36) [19]	Interview	X		X
Preference regarding diagnostic evaluation of suspected cognitive impairment	Added questions	Interview and informed consent PN	X	X	X
Informal caregiver
Quality of life	MDS & EQ5D	Questionnaire	X	X	X
Psychopathology	GHQ12 [20]	Interview	X		X
Sense of competence to provide care	SSCQ [21]	Interview	X	X	X
Potential effect-modifiers / confounders
Individual with suspected cognitive impairment
Sociodemography	By proxy	Interview	X
Morbidity	By proxy	Interview	X
Behavioural symptoms	NPI [22]	Interview	X		X
Informal caregiver
Sociodemography	MDS	Interview	X
Social support	SSL12 [23]	Questionnaire	X		X
Duration and intensity of caring	Added Q	Interview	X
GP / Primary Care Practice
Age GP	Added question	Questionnaire
Sex GP	Added question	Questionnaire
Presence of practice nurse for elderly patients	Added question	Questionnaire
Attitude to diagnosis and care for individuals with dementia	Added questionnaire [24]	Questionnaire
Percentage patients ≥ 65 years	-	Medical records
Cluster size	-	Medical records

CAMCOG = Cambridge Cognitive Examination, MDS = Minimal Dataset ZonMW, QoL-AD = Quality of Life in Alzheimer’s Disease, EQ5D = EuroQol utility questionnaire; 5 questions, MH5 (SF36) = 5 questions on Mental Health of the Short Form 36 questionnaire, GHQ12 = General Health Questionnaire, SSCQ = Short Sense of Competence Questionnaire, NPI = Neuropsychiatric Inventory, SSL12 = short version of the Social Support List.