Table 2 Outcome measures for THINK-MED pilot RCT

Mediterranean Diet Score [44]

A change in MDS at 6 months, with a maintenance of score by 12 months.

This 14-item MDS was adapted from the validated MDS used in the PREDIMED study [45] for use among Northern European populations. The overall aim was to increase MDS by ≥ 3 points at month 6 (adoption) and month 12 (maintenance) (if applicable). The questionnaire contained 14 items based on consumption of a component of the MD. Each item was scored either zero or one. The maximum score which could be obtained was 14, with a score of zero indicating a low adherence to a MD and 14 indicating the greatest adherence.

Feasibility

Recruitment (recruitment rates, time taken for the recruitment of participants, characteristics of recruited sample as against expected, non-response rates, reasons for non-response)

Retention and completion (retention rates, number of drop outs and reasons for withdrawal, follow-up response rates (6 months and 12 months of follow-ups)

Data collection methods and study procedures (Feasibility of measurement tools - time taken to fill in questionnaires, missing data from questionnaires, understanding level of procedures and measurement protocols, suitability of outcome measures, sensitivity of outcome measures to change)

Acceptability and adherence to intervention (barriers to participation, burden (reasons for not taking part/discontinuation or dropping out, study evaluation questionnaire))

Cognitive function

A change in cognitive test score at 6 months, with a maintenance of score by 12 months.

A comprehensive cognitive assessment was performed using a validated neuropsychological test battery provided by Cambridge Cognition Ltd. (CANTAB). This involved seven tests specific and sensitive to a MCI population. Tests included: Motor Screening Task (MOT), Reaction Time (RTI), Paired Associates Learning (PAL), Pattern Recognition Memory (PRM), Delayed Matching to Sample (DMS), Spatial Working Memory (SWM) and Rapid Visual Information Processing (RVP).

Physical activity

RPAQ-Recent Physical Activity Questionnaire [48]

Anthropometry

Height (m), Weight (kg), BMI (kg/m²), waist circumference (cm), hip circumference (cm), waist to hip ratio

Muscle strength

Measured by a hand grip-strength dynamometer

Blood pressure

Branchial blood pressure was obtained using a calibrated Omron automated monitor (British Hypertension Society approved).

Demographic and medical history

Demographic, lifestyle and medical questionnaire (baseline) and change in lifestyle questionnaire (6/12 months)

Instrumental activities of daily living (IADL)

IADL scale by Lawton and Brody (1969) [49] and Bristol activities of daily living (ADL) scale (Bucks et al. 1996) [50]

Depression

Geriatric Depression Scale (GDS) (short form) [51]

Quality of life

Rand 36-item validated questionnaire [52]

Health beliefs

Previously validated questionnaire based on components of the Health Belief Model [53] which was modified for use within the TEAM-MED study [44]

Dietary behaviour change

MD staging algorithm [54]

MD knowledge (adapted from Parmenter and Wardle, 1999) [55]

Barriers to MD dietary change (based a questionnaire devised from on previous focus group analyses with a Northern European population used within the TEAM-MED study [44])

MD self-efficacy [56]

4 day food diary to capture dietary intake and measure MD compliance

Study evaluation

Data collected via questionnaire on evaluation of study procedures and tolerance towards a MD

Blood sample

50 ml blood sample was taken from all participants to be stored for future analysis of biomarkers of MD adherence and biomarkers of neurodegenerative disease risk