Correct syntax for matching something in an array (split)?

I have a Radio button that I want to ‘check’ if a value matches a value in a comma separated list which comes from a database field. This needs to be done at the Input field and so I cannot use the IN function of a Query. This is what I have tried so far but doesn’t work.

dmx-bind:checked="specialist_id == sc_ad_job_q.data.sa_q_job_q[0].meth_specialist_ref.split(',')"

where

• specialist_id = 33_1

and

• meth_specialist_ref = 34_1,33_1,32_3

If I do a simple
dmx-bind:checked="specialist_id == '33_1'"
then it works fine