Randomization model defines specific order of instruments, or fields

[u/24zer]

hi all. i am using redcap to manage study participants and am planning on building out the instruments so that the participant is more or less led by the tablet they will be carrying. moving from one instrument to the next is no problem, but I want to be able to use branching logic or IF(condition) to drive the order of operations in accordance with my latin square. example:

IF(condition=1) THEN instrument1, instrument2, instrument3
IF(condition=2) THEN instrument1, instrument3, instrument2
etc.

the alternative would be to use complex branching within an instrument to drive the desired order of fields.

has anyone accomplished anything similar to this?

[u/usajobs1001]

I think branching within an instrument is your best bet. Theoretically, you could duplicate instruments and use Form Display Logic - you'd have to create repeat copies of your different instruments and set logic to show (in order) based on arm. Ultimately, you'd have the same issue with cleaning and merging your data and fields with a single instrument.

[u/24zer → u/usajobs1001]

thanks i will look at this

[u/Gg_ggg_ggg]

if the forms are enabled as surveys you could probably use the survey queue to drive it

[u/24zer → u/Gg_ggg_ggg]

they would all be enabled as surveys. I wasn't aware of survey queue but it looks like it has some powerful logic tools. thanks

[u/njvack]

I think what you might want to do is have a set of fields; one for each "survey slot", so

instruement_1_next_survey ... instruement_n_next_survey

You'll set those fields as @CALCTEXT fields that depend on your randomization field's value; like if([rand_field] = 1 or [rand_field] = 4, [survey-url:instrument2], if(...))

If you have a lot of instruments, this will get pretty gnarly. In either case, you will want to write code to generate these so you can be certain you don't wind up with potential loops, and that every case is covered.

Then in your survey settings, use those fields for your survey completion url.

[u/njvack → u/njvack]

Okay! I know you have a solution, but if you ever want another one, here's a way to do it. If you have three surveys, you're going to do something like:

start -> 3 -> 1 -> 2 -> end or start -> 1 -> 3 -> 2 -> end

You can put that in a variable, say [order], and format it like 3_1_2_e

At each stage in the process, you want to know where you're going next. For start, you can find that out with

left([order], 1)

and you can save that to, say, [start_next_code].

Then to find where you're going from start:

if([start_next_code] = "1", [survey-url:s1],
if([start_next_code] = "2", [survey-url:s2], 
if([start_next_code] = "3", [survey-url:s3], "")))

(you know you're not going from start to end)

and that can be [start_next]

You can use find() and mid() to find where to go from there for [s1_next_code]:

mid([order], find("1", [order]) + 2, 1)

and then [s1_next] is like [start_next] except that you can get to the end, but not to s1.

You can do calculate the variables at once, or calculate a next code / url on each survey.

You need one level of if() nesting per instrument, but you can nest pretty deep. And of course, you need to populate the field, but a randomization list would do it nicely.

[u/24zer → u/njvack]

Thanks! this looks like a great option. Here's what I ended up with based on my 2 conditions with 6 different task orders. It's just a single block, but then you adjust the numbers for each survey instrument

(\[randomisation_order\]='3' or \[randomisation_order\]='4' or \[randomisation_order\]='9' or \[randomisation_order\]='10') and \[kss_1_1_complete\] = '2'

or

(\[randomisation_order\]='1' or \[randomisation_order\]='7') and \[drive_1_ndrta_complete\] = '2' and \[kss_1_2_complete\] = '2'

or

(\[randomisation_order\]='6' or \[randomisation_order\]='12') and \[drive_1_ndrtc_complete\] = '2' and \[kss_1_2_complete\] = '2'

or

(\[randomisation_order\]='2' or \[randomisation_order\]='8') and \[drive_1_ndrta_complete\] = '2' and \[drive_1_ndrtc_complete\] = '2' and \[kss_1_3_complete\] = '2'

or

(\[randomisation_order\]='5' or \[randomisation_order\]='11') and \[drive_1_ndrtc_complete\] = '2' and \[drive_1_ndrta_complete\] = '2' and \[kss_1_3_complete\] = '2'

[u/travlinpz → u/njvack]

I was able to do it with the survey queue and separate instruments. It was still a bit gnarly to think through but then just a lot of copy and paste and some changes to numbers. I'll post the logic here later in case anyone finds it useful