A Brief GAmeplay Intervention for NHS ICU Staff Affected by COVID-19 Trauma (GAINS Study)

Number of intrusive memories of traumatic event(s) recorded by participants in a brief daily online diary for 7 days.

Total number of intrusive memories reported in Week 4 compared to run-in/screening week for the immediate intervention group and Week 8 compared to Week 4 for the delayed intervention group (i.e., within-group comparisons).

The 9-item questionnaire assesses a number of intrusive memories characteristics. These characteristics include frequency (7-point categorical response from 'never' to 'many times a day); distress (0=not at all to 10=extremely); disruption to concentration (0=not at all to 10=extremely); interference with what you were doing (how much (0=not at all to 10=extremely) and for how long (6-point categorical response from '<1min' to '+60mins')); impact on work functioning (0=not at all to 10=extremely) and in what ways (open text response)); impact on functioning in other areas of life (how much (0= not at all to 10 = extremely) and in what ways (open text response)).

Five quantitative outcomes are presented here. For two further ordinal items, frequency and duration of interference, please see below.

The 9-item questionnaire assesses a number of intrusive memories characteristics. Five ordinal items are presented separately (see "Intrusive Memory Ratings, ordinal items"). Here we present one of the two categorical items. This item assesses the frequency of intrusive memories over the past week (7-point categorical response from 'never' to 'many times a day').

The 9-item questionnaire assesses a number of intrusive memories characteristics. Five ordinal items are presented separately (see "Intrusive Memory Ratings, ordinal items"). Here we present one of the two categorical items. This item assesses the duration for which an intrusive memory interfered with with what participants were doing (6-point categorical response from '<1min' to '+60mins').

This 22-item questionnaire assesses subjective distress after a traumatic event (with reference to the events for which participants are taking part in the study).

Items are rated for how distressing they have been during the past 7 days on a 5-point ordinal scale ranging from 0 ("not at all") to 4 ("extremely"). The measure consists of three subscales with subscale and total scores calculated as the mean of all items: intrusion subscale (8-items, score range 0-4), avoidance subscale (8-items, score range 0-4) and hyperarousal subscale (6-items, score range 0-4), and total score (all 22-items, score range 0-4). We will analyse total score as the mean of all 22-items, and subscales as the mean of items in each subscale separately. Higher scores indicate higher levels of subjective distress after a traumatic event.

This shortened 4-item version of the PCL-5 assesses symptoms of PTSD over the last month.

Items are rated on a 5-point scale ranging from 0 ("not at all") to 4 ("extremely"). Total score ranges from 0 to 16 (cut-off for possible PTSD is 10 or above).

This 8-item scale measures sleep problems against the DSM-5 criteria for insomnia disorder.

Item responses are each scored 0-4, with scores from 0 to 2 indicating threshold criteria for insomnia disorder. Total score ranges 0-32, with a higher score indicating better sleep (cut-off for possible insomnia disorder is a total score from 0 to 2).

Items are rated for how often they have bothered the respondent over the last two weeks, from 0 ("not at all") to 3 ("nearly every day"). Total score is the sum of both items and ranges from 0 to 6 (cut-off for possible GAD is 3 or above).

This 2-item short-form self-report measure assesses symptoms of depression.

Items are rated for how often they have bothered the respondent over the last two weeks, from 0 ("not at all") to 3 ("nearly every day"). Total score is the sum of both items and ranges from 0 to 6 (cut-off for possible major depressive disorder is 3 or above).

This measure consists of 4 questions that are scored and designed to assess the impact of a person's intrusive memories.

Questions 1b, 2b, 3b, and 4 are scored. These have a six-point ordinal scale ranging from 0 to 5 and are summed to generate a total score from 0 to 20. Higher values indicate the person is more severely affected.

The 12-item, self-report version of the WHODAS 2.0 will be used to assess difficulties in relation to the impact of intrusive memories.

Respondents rate how much difficulty they have had in each area in the past 30 days, from 0 (none) to 4 (extreme or cannot do). The overall score is calculated as a percentage of the maximum possible score (i.e., 48 points).

The 5-level version of the EuroQol-5D (EQ-5D-5L) is a brief measure for assessing general quality of life and health status.

Items assess mobility, self-care, usual activities, pain/discomfort and anxiety/depression each on a 5-point scale. 5 items are scored on a 5-point ordinal scale from 'no problem' (1) to 'highest level of problems' (5). Respondents also self-rate their overall health today on a visual analogue scale from 0 (the worst health you can imagine) to 100 (the best health you can imagine). Scores are analysed separately (not summed).

Here we present the 'overall health' visual analogue scale item.

This 19-item self-report measure assesses work engagement and burnout. Respondents rate how often they have felt each descriptive item in the past two weeks, from 1 (not at all) to 4 (all the time).

The work engagement subscale consists of 10-items assessing three dimensions (attentiveness, vigour, and dedication) with each dimension consisting of 4-, 3-, and 3-items respectively. Greater scores indicate a higher (i.e., better) degree of work engagement.

The burnout subscale consists of 9-items assessing three dimensions (Engagement, Exhaustion, and Disengagement), with each dimension consisting of 3-items. Greater scores indicate a higher (i.e., functionally worse) degree of burnout.

A mean score is calculated for the work engagement and burnout subscales, from individual items (for both subscales, scores range 1-4).

Single item assessing self-reported number of sick days taken from work in the last 4 weeks. Total scoring includes total number of sick days.

This 3 items questionnaire is used to assess participants' intention to leave their job e.g. "I think a lot about leaving the job", each rated from 1 (strongly agree) to 5 (strongly disagree). The total score ranges 3 to 15, with a lower score indicating stronger intention to leave the job.

One item asses the number of days worked in the last week (both with responses from 0 to 7 days).

One item asses the number of night shifts worked in the last week (both with responses from 0 to 7).