At each time point, participants self-reported if they have taken any steps to reduce firearm access for the person with dementia. Nine response options associated with this question are used to calculate this binary outcome (1+ actions taken versus no action taken). If they selected 'yes' to any of the following options, their outcome was '1+ action taken' (1); if they selected 'no' to all, their outcome was 'no action taken' (0). The nine response options were: (1) used a/more locking devices, (2) used a/more locking safes or gun lockboxes, (3) gave a/more guns to a trusted family member for temporary safekeeping, (4) gave a/more guns to a trusted friend for temporary safekeeping, (5) stored a/more guns at a store or range that has firearm storage, (6) stored a/more guns at a law enforcement agency temporarily, (7) gave a/multiple guns to law enforcement permanently, (8) sold, gave or transferred a/multiple guns to family or friends, and (9) sold a/multiple guns to the public.

We will assess injuries involving the person with ADRD and a firearm. Participants will be asked about any such incidents in the prior year (baseline) or since enrollment (follow-up) and a brief description.

The short-form Zarit Burden Interview has scores ranging from 0-48, calculated from 12 items (measured on a 5-point scale from 0, never to 4, nearly always); scores range from 0 to 12 with higher scores reflecting higher burden.

The Positive Aspects of Caregiving Scale has scores ranging from 0-36, calculated from the sum of 9 items (measured on a 5-point scale ranging from 0, disagree a lot, to 4, agree a lot, on statements such as feel more useful), with higher scores indicating more positive caregiving experiences.

Safety in Dementia is an online tool that, in a stepwise fashion, guides a caregiver individual through decisions related to firearm access for a person with dementia. It includes information and a comparison of the options and their risks and benefits. It guides the caregiver through clarification of personal feelings and values and identifying their decision/plan.

Safety in Dementia: Safety in Dementia is an online tool that, in a stepwise fashion, guides a caregiver individual through decisions related to firearm access for a person with dementia. It includes information and a comparison of the options and their risks and benefits. It guides the caregiver through clarification of personal feelings and values and identifying their decision/plan. The control group will view national Institute on Aging Home Safety Checklist.

Total of all reporting groups

N = 13 participants were missing age responses at baseline (N = 8 control, N = 5 Safe at Home).

N = 15 participants' responses were missing to this question (N = 8 control, N = 7 Safe at Home).

The Preparation for Decision Making Scale assesses perception of how useful a decision aid is in preparing for subsequent decision-making. Scores range from 1-5, calculated from the sum of 10 constructs (each ranging from 1, 'not at all' to 5, 'a great deal'). The total score is calculated by first summing the 10 items and dividing by 10 to find an average item response score. Then, we subtract 1 from the summed score and multiply this by 25 to convert the final score to a 0-100 scale with higher scores indicating higher perceived levels of preparation for decision making (higher = better).

This outcome was measured at baseline post-randomization (post-intervention), not before randomization. Participants were required to respond to all variable components of the scale to have their outcome calculated, so N = 33 participants' preparation for decision-making scale scores could not be calculated.

The control group will view National Institute on Aging Home Safety Checklist.

Safety in Dementia: Safety in Dementia is an online tool that, in a stepwise fashion, guides a caregiver individual through decisions related to firearm access for a person with dementia. It includes information and a comparison of the options and their risks and benefits. It guides the caregiver through clarification of personal feelings and values and identifying their decision/plan. The control group will view national Institute on Aging Home Safety Checklist.

Safety in Dementia is an online tool that, in a stepwise fashion, guides a caregiver individual through decisions related to firearm access for a person with dementia. It includes information and a comparison of the options and their risks and benefits. It guides the caregiver through clarification of personal feelings and values and identifying their decision/plan.

Safety in Dementia: Safety in Dementia is an online tool that, in a stepwise fashion, guides a caregiver individual through decisions related to firearm access for a person with dementia. It includes information and a comparison of the options and their risks and benefits. It guides the caregiver through clarification of personal feelings and values and identifying their decision/plan. The control group will view national Institute on Aging Home Safety Checklist.

The Decision Self-Efficacy Scale measures confidence in ability to make decisions; transformed scores range from 0 (extremely low, worst outcome) to 100 (extremely high self-efficacy, best outcome).

N = 496 of 500 participants had sufficient data to calculate decision self-efficacy at at least one time point when it was measured (baseline, 2 week, 2 month, and/or six month).

Firearm access for the person with ADRD will be assessed with scales we have used in prior work, allowing nuanced (but efficient) description of firearm access (on a scale ranging from access to multiple loaded firearms to no access to any firearms). For reporting and analysis, we will use binary categorization (caregiver reports that person with dementia still has access to 1+ firearm [1] versus person with dementia no longer has access to any firearms [0])

N = 489 of 500 participants have at least one follow-up measure of person with dementia (PWD) firearm access.

At each time point, participants self-reported if they have taken any steps to reduce firearm access for the person with dementia. Nine response options associated with this question are used to calculate this binary outcome (1+ actions taken versus no action taken). If they selected 'yes' to any of the following options, their outcome was '1+ action taken' (1); if they selected 'no' to all, their outcome was 'no action taken' (0). The nine response options were: (1) used a/more locking devices, (2) used a/more locking safes or gun lockboxes, (3) gave a/more guns to a trusted family member for temporary safekeeping, (4) gave a/more guns to a trusted friend for temporary safekeeping, (5) stored a/more guns at a store or range that has firearm storage, (6) stored a/more guns at a law enforcement agency temporarily, (7) gave a/multiple guns to law enforcement permanently, (8) sold, gave or transferred a/multiple guns to family or friends, and (9) sold a/multiple guns to the public.

N = 497 of 500 participants reported on actions to reduce firearm access at at least one time point (baseline, 2 week follow-up, 2 month follow-up, and/or 6 month follow-up).

We will assess injuries involving the person with ADRD and a firearm. Participants will be asked about any such incidents in the prior year (baseline) or since enrollment (follow-up) and a brief description.

N = 500 participants had data at at least one time point; missing responses at later time points are due to missing visits, withdrawn participants, or participants choosing to skip this question.

The short-form Zarit Burden Interview has scores ranging from 0-48, calculated from 12 items (measured on a 5-point scale from 0, never to 4, nearly always); scores range from 0 to 12 with higher scores reflecting higher burden.

This scale was measured at 2 week follow-up, so missing values are due to missed 2 week follow-up visits or participants skipping questions on this scale.

The Positive Aspects of Caregiving Scale has scores ranging from 0-36, calculated from the sum of 9 items (measured on a 5-point scale ranging from 0, disagree a lot, to 4, agree a lot, on statements such as feel more useful), with higher scores indicating more positive caregiving experiences.

N = 461 participants had sufficient data at 2 week follow-up to calculate Positive Aspects of Caregiving; missing data is due to missed 2 week follow-up visits or participants skipping questions on this scale.

Safety in Dementia is an online tool that, in a stepwise fashion, guides a caregiver individual through decisions related to firearm access for a person with dementia. It includes information and a comparison of the options and their risks and benefits. It guides the caregiver through clarification of personal feelings and values and identifying their decision/plan.

Safety in Dementia: Safety in Dementia is an online tool that, in a stepwise fashion, guides a caregiver individual through decisions related to firearm access for a person with dementia. It includes information and a comparison of the options and their risks and benefits. It guides the caregiver through clarification of personal feelings and values and identifying their decision/plan. The control group will view national Institute on Aging Home Safety Checklist.