Table 1.

Data-Collection Components According to Inclusion in Per-Protocol Completion Measure, Study to Explore Early Development, 2007–2011

Componenta	Included in Per-Protocol Completion Measure?b
SCQ administered to primary caregiver via phone at enrollment	Not applicable
Medical records release: prenatal care, labor and delivery, neonatal care, and pediatric care (Consent and medical provider release forms included in initial enrollment packet, but medical records abstraction typically occurred much later in the study.)
Provision of release to review at least 1 medical record from mother or childc	Yes
Questionnaire Packet 1 (mailed to primary contact and self-administered/caregiver-administered or completed with study staff assistance via phone or in person)
Maternal and family medical history forms: maternal medical history, family autoimmune history, and child gastrointestinal function questionnaire	Yes
Paternal formsd: paternal medical history form and paternal occupational history form	No
Child development form: early development questionnaire (potential-ASD protocol families only)	Yes
PCI about family sociodemographic factors, maternal reproductive history and pregnancy health and behaviors, and early child development (administered via phone to mother and/or other primary caregiver)	Yes
Questionnaire Packet 2 (mailed to primary contact and self-administered/caregiver-administered, or completed with study staff assistance via phone or in person)
Child behavioral development forms: Child Behavior Checklist, Carey Temperament (or Behavioral Styles) Scales (depending on child’s age), Social Responsiveness Scale (preschool or child version, depending on child’s age), and sleep habits questionnaire	Yes
Services and treatment questionnaire (potential-ASD protocol families only)	Yes
Maternal forms: Social Responsiveness Scale (adult version)	No
Paternal formsd: Social Responsiveness Scale (adult version)	No
In-person evaluation(s) (1 or more in-person visits in clinical setting or child’s home; included several components involving child and primary caregiver and/or biological parents)
Developmental assessments	Yes (as applicable)
Mullen Scales of Early Learning (potential-ASD and main (POP and DD) protocol families)
Vineland Adaptive Behavior Scale–II (potential-ASD protocol familiese)
Autism Diagnostic Interview–Revised (potential-ASD protocol families only)
Autism Diagnostic Observation Scale (potential-ASD protocol families only)
Dysmorphology examinationf	Yes
Biological samples (buccal swabs self/parent-collected; blood and hair specimens collected in person by study staff)
Child: buccal swabs and/or blood	Yes
Mother: buccal swabs and/or blood	Yes
Father: buccal swabs and/or bloodd	No
Child: hair sample	No
Questionnaire Packet 3g (provided to primary caregiver as a single booklet during final in-person visit with instructions to complete and return to study site)
Child 3-day diet and 7-day stool diary	No

Abbreviations: ASD, autism spectrum disorder; DD, developmental delay; PCI, Primary Caregiver Interview; POP, population controls; SCQ, Social Communication Questionnaire.

^aData-collection components listed in the usual chronological order of offer to study respondents except buccal swabs. Buccal swab self-collection kits were mailed to families at enrollment. If not received by the time of in-person evaluation, they were requested then. Completion and return of forms included in Questionnaire Packets 1 and 2 occurred throughout the data-collection period. In some instances, multiple follow-up calls were made to remind participants to complete the forms, and/or forms were completed with assistance from staff via phone or during the in-person evaluation.

^bPer-protocol completion measure was developed for operational purposes (as opposed to being tied to any specific scientific study objectives). However, inclusion of selected components would contribute most to analyses of main study research questions. This measure was used throughout the study to assist sites in monitoring progress. Completion of every study component was pursued equally, but participants could refuse any component and continue with other aspects of the study. For most scientific analyses, the actual number of children who could be included is substantially higher than the number considered complete for all components of per-protocol measure.

^cMedical records component was considered complete if 1 or more medical provider release forms were returned to project staff. However, in some instances medical provider releases were provided, but medical records could not be abstracted because records could not be obtained from the provider or incomplete records were sent by the provider.

^dPaternal forms and samples were not always possible to collect for reasons other than refusal (e.g., father deceased, father not in touch with mother/primary caregiver, father unknown).

^eVineland Adaptive Behavior Scale II could be administered to main (DD or POP) families if child’s performance on composite score of Mullen Scales of Early Learning fell below the standard.

^fDysmorphology examination component was considered complete if the examination form was completed. However, in a small number of instances, examination photos could not be obtained from child. These children could not be included in analyses requiring dysmorphology data even though they had completed the examination.

^gQuestionnaire Packet 3 consisted of 3-day diet and 7-day stool diaries, combined into a single booklet. This packet was given only to families who were seen for the in-person evaluation because the instructions for recording diet and stool quality information required in-person interaction with caregivers.