Outcome
Type |
Measure |
Description |
Time frame |
Safety issue |
Primary |
Symptoms of depression and anxiety |
Symptoms of depression and anxiety as measured by the Patient Health Questionnaire Anxiety and Depression Scale (PHQ-ADS). This is a 15-item self-report likert scale comprising the PHQ-8 and GAD-7. Scores can range from 0 to 48, cut points of 10,20 and 30 indicate mild, moderate and severe levels of depression/anxiety respectively. |
Week 0 and 12 |
|
Secondary |
Functional impairment |
The self-report Work and social adjustment scale (WSAS) will be used to measure functional impairment scores. This is a self-report likert scale with 5 questions. Responses range from Not at all (0) to Very severely (8). 0-9, 10-19 and 20-40 represent low, moderate and severe impairment respectively. |
Weeks 0,6 and 12 |
|
Secondary |
Sleep quality |
The self-report Pittsburgh sleep quality index (PSQI) will be used to measure sleep quality. This is a 19-item questionnaire with seven subcategories; subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. |
Weeks 0,6 and 12 |
|
Secondary |
Wellbeing |
The self-report world health organisation five well-being index (WHO-5) will be used to measure wellbeing. The scale consists of 5 items rated from All of the time (5) to At no time (0). |
Weeks 0,6 and 12 |
|
Secondary |
Quality of life |
The self-report World Health Organisation Quality of Life Brief (WHOQOL-BREF) scale will be used to measure quality of life. This is a 26-item scale. Responses are rated on a 1-5 likert scale with 1 representing 'not at all' and 5 representing 'completely agree'. Scores are tabulated and multiplied by 4 to represent a score out of 100. |
Weeks 0,6 and 12 |
|
Secondary |
Physical activity |
The self-report international Physical Activity Questionnaire - Short form (IPAQ) will be used to measure physical activity. |
Weeks 0,6 and 12 |
|
Secondary |
Symptoms of depression |
The self-report Patient Health Questionnaire-8 (PHQ-8) will be used to measure symptoms of depression. The PHQ-8 is comprised of 8 items rated 0 to 3 with 0 representing 'not at all' and 3 representing 'nearly every day'. |
Weeks 0,6 and 12 |
|
Secondary |
Symptoms of anxiety |
The self-report Generalised Anxiety disorder-7 scale will be used to measure symptoms of anxiety. The GAD-7 is comprised of 7 questions rated 0 to 3 indicating not at all, to nearly every day respectively. |
Weeks 0,6 and 12 |
|
Secondary |
Psychological Distress |
The Kessler Psychological Distress Scale (K10) will be used to measure symptoms of psychological distress. The K10 is comprised of 10 questions rated on a 5-point likert scale. Scores range from 10-50. |
Weeks 0,6 and 12 |
|
Secondary |
Faecal gut microbiota (composition, alpha- and beta-diversity) |
Measured by 16S community profiling (Illumina Miseq) of bacterial genomic DNA isolated from stool samples. |
Week 0 and 12 |
|
Secondary |
Faecal short-chain fatty acids (SCFA) |
Measured by gas liquid chromatography of stool samples |
Week 0 and 12 |
|
Secondary |
Faecal water |
Determined from stool samples by oven-drying |
Week 0 and 12 |
|
Secondary |
Gut symptoms |
Measured using the Gastrointestinal Symptom Rating Scale (GSRS) (7-day diary; questionnaire) |
Week 0 and 12 |
|
Secondary |
Stool frequency |
Measured using self-reported number bowel movements daily recorded in a 7-day diary. |
Week 0 and 12 |
|
Secondary |
Stool consistency |
Measured using the Bristol stool form scale (7-day dairy; questionnaire) |
Week 0 and 12 |
|
Secondary |
Serum Vitamin E levels |
Measured in blood sample. Analysis of serum vitamin E levels by Liquid chromatography-mass spectrometry. |
Week 0 and 12 |
|
Secondary |
Dietary intake |
Measured using a 7-day food and drink diary |
Week 0 and 12 |
|
Secondary |
Acceptability of snack products |
Measured using an Acceptability of dietary intervention questionnaire developed by King's College London for use in dietary intervention studies. The questionnaire assesses acceptability using a number of domains including flavour, texture and portion size. |
Week 12 |
|
Secondary |
Snack compliance |
Measured via the return of unused snacks at the final visit (consumption of >75% of total snacks will be considered compliant). |
Week 12 |
|
Secondary |
Adverse events |
Interview-administered questionnaire |
Week 0 to 12 |
|
Secondary |
Symptoms of depression and anxiety |
Symptoms of depression and anxiety as measured by the Patient Health Questionnaire Anxiety and Depression Scale (PHQ-ADS). This is a 15-item self-report likert scale comprising the PHQ-8 and GAD-7. Scores can range from 0 to 48, cut points of 10,20 and 30 indicate mild, moderate and severe levels of depression/anxiety respectively. |
Week 0,6 and 12 |
|
Secondary |
Change in symptoms of depression and anxiety |
Change symptoms of depression and anxiety as measured by the Patient Health Questionnaire Anxiety and Depression Scale (PHQ-ADS). This is a 15-item self-report likert scale comprising the PHQ-8 and GAD-7. Scores can range from 0 to 48, cut points of 10,20 and 30 indicate mild, moderate and severe levels of depression/anxiety respectively. |
Week 0, 6 and 12 |
|
Secondary |
Proportion of people with no, mild, moderate and severe symptoms of anxiety and depression |
Measured by the Patient Health Questionnaire Anxiety and Depression Scale (PHQ-ADS). This is a 15-item self-report likert scale comprising the PHQ-8 and GAD-7. Scores can range from 0 to 48, cut points of 10,20 and 30 indicate mild, moderate and severe levels of depression and anxiety respectively. |
Week 0, 6 and 12 |
|
Secondary |
Proportion of people with no, mild, moderate and severe symptoms of depression |
Measured by the PHQ-8 questionnaire. Scores can range from 0 to 24, cut points of 5, 10, 15 and 20 indicate mild, moderate, moderately severe and severe levels of depression, respectively. |
Week 0, 6 and 12 |
|
Secondary |
Proportion of people with no, mild, moderate and severe symptoms of anxiety |
Measured by the GAD-7. The GAD-7 is comprised of 7 questions rated 0 to 3 indicating not at all, to nearly every day respectively and scores range from 0-21. Cut points are 5, 10 and 15 indicating mild, moderate and severe levels of anxiety, respectively. |
Week 0, 6 and 12 |
|