Supplementary Appendix A. Code Book (Atlas.ti)

Thematic
Code / Definition
about us / Describes Facebook campaign and/orUniversity of Michiganengagement.
altruism / Comment implies or refers to altruistic motivation, responsibility, or the ‘greater good' underlying donation or use of bloodspots for health research. Includes comments expressed positively (e.g., DBS should be donated) or negatively (e.g., it would be selfish to not donate).
awareness / Comment relates to personal or public awareness (or lack of awareness) of Michigan’s newborn screening or biobanking programs.
benefits / Comment or question relates to the benefits of using DBS for health research, or refers to health research as a positive end.
birthplace / Commenter responds to prompt to let us know where they or their kid/s were born in Michigan (e.g., Detroit; Saginaw; My daughter was spotted in Lansing). The quotation has no other substantive content.
bloodspot use / Comment refers to or inquires about how DBS are used, including specific health research uses.
chatter / Personal conversation or socializing, not related to biobanking or newborn screening (NB: does not include grammar or birthplace, which are coded separately)
clone / Comment or question mentions cloning
consent / Comment or question related to the consent process or consent options, including opting in or out.
cord blood / Comment or question refers to cord blood
destroy / Comment or question implies or refers to a preference to not participate, to opt out, or to have bloodspots destroyed, or provides information about how to do so.
DNA / Comment or question refers to DNA or genetics.
government / Comment refers to government.
grammar / Comment discusses spelling and/or grammar.
health conditions / Comment refers to a particular health condition
identifiability / Comment or question regarding identifiability or anonymity of bloodspots.
inclusion / Comment refers to, discusses, or inquires about an individual’s inclusion in the biobank, or criteria for inclusion. E.g, How do I know if I am in the biobank? Is my daughter in it? What years apply? What about other states? etc
law / Comment is related to the legal system, legality, or laws. This might include a) questions or comments about laws in place to protect privacy; b) questions or comments questioning the legality or constitutionality of biobank practices; or c) questions or comments about the use of bloodspots for forensic or law enforcement purposes.
ROR / Comment refers directly or indirectly to return of research results.
newborn screening / Comment is primarily or directly about newborn screening
privacy / Comment conveys a concern about privacy, broadly defined so as to include the following concepts: constitutional rights (e.g., 4th amendment); control over personal information; concerns about the sensitivity of data (e.g., DNA content, identifiability); concerns about the consent process (e.g., collected without asking); surveillance; privacy laws, governmental intrusion or “overstepping."
Attitudinal/
Emotive Codes / Definition
conflicted / Comment explores mixed feelings or tradeoffs
judgement / Comment includes a judgement about other people's perspectives, attitudes, or attributes: e.g., “sheepal,” “stupid,” “paranoid,” “naive,” “drinking the Kool Aid,” etc.
lol / Comment seems to be conveyed with humor, often contains the phrase LOL or a smile emoticon.
negative / Comment conveys the fbuser has negative feelings about Michigan’s biobank
nbd / Comment implies the user does not care about this issue, doesn’t see any reason to take issue, or contains the phrase, “No big deal"
positive / Comment conveys a positive attitude about Michigan’s biobank
surprised / [no entry]
trust / Comment conveys trust or mistrust underlying attitudes about biobanking, e.g., references to paranoia, naivety, gullability, conspiracy, surveillance.
Discursive/
Comment codes / Definition
Answer / Answer addresses a previous information-seeking comment Response, includes repsones in and out of threads, e.g., might be responding to previous comments in general
Clarification / Comment provides a correction or clarification of a previous post
fbuser / The comment or question is posed by a Facebook user
Includes link / Comment includes a link to an external source, most often: MDHHS (Consent information, research uses); Mybloodspot.org FAQ, Babiesfirsttest.org)
Includes photo / Comment includes a photo, including a selfie, meme, or other image files
Mistake / Comment includes or conveys a mistake or misunderstanding
Moderator initiated / [no entry]
Personal experience / Comment refers to a personal experience
Question / ■ / Comment seeking information, usually posed as a question.
Question/
mistake not addressed / ■ / Moderator does not answer a question posed by a FB user or does not provide a clarification
Tag / ■ / Commenter tagged one or more other FB users in the post
Thread / ■ / Set of related comments