Fig. 1

Study flow chart illustrating participant recruitment and allocation to repetitive head impact exposure groups and diagnostic groups for data analyses. Abbreviations: RHI, repetitive head impacts; CMD, Complaints-Memory-Dementia algorithmic grouping; CN, cognitively normal; SMC, subjective memory complaint; MCI, mild cognitive impairment; DEM, dementia; SUVR, standard uptake value ratio; NA, not applicable; TOMM, Test of Memory Malingering, CMD algorithmic approach for diagnostic grouping: Presence or absence of subjective cognitive complaints, C ± (C + defined by Cognitive Complaint Index [memory items] self-report score > 16); presence or absence of objective memory impairment, M ± (M + defined by NAB List Learning Test Delayed Recall T score ≤ 35); presence or absence of dependence in daily functioning, D ± (D + defined as Functional Activities Questionnaire score ≥ 9)