mtl <-
structure(list(subject = c(9690L, 9722L, 9735L, 9787L, 10010L, 
10021L, 10114L, 10127L, 10134L, 10138L, 10145L, 10161L, 10172L, 
10181L, 10192L, 10201L, 10203L, 10208L, 10213L, 10214L, 10217L, 
10220L, 10221L, 10227L, 10229L, 10230L, 10231L, 10240L, 10241L, 
10278L, 10283L, 10289L, 50028L, 50034L, 50042L), sex = c("M", 
"M", "F", "F", "F", "F", "F", "F", "F", "F", "M", "M", "M", "F", 
"F", "F", "F", "F", "F", "F", "F", "F", "M", "F", "M", "F", "F", 
"F", "M", "F", "M", "M", "F", "F", "F"), ethnic = c("Caucasian", 
"Other", "Caucasian", "Caucasian", "Caucasian", "Caucasian", 
"Caucasian", "Caucasian", "Caucasian", "Other", "Caucasian", 
"Caucasian", "Caucasian", "Caucasian", "Caucasian", "Other", 
"Other", "Caucasian", "Caucasian", "Caucasian", "Caucasian", 
"Caucasian", "Caucasian", "Caucasian", "Caucasian", "Other", 
"Caucasian", "Caucasian", "Caucasian", "Caucasian", "Caucasian", 
"Other", "Caucasian", "Caucasian", "Caucasian"), educ = c(14L, 
20L, 14L, 14L, 18L, 18L, 14L, 18L, 18L, 14L, 23L, 12L, 18L, 18L, 
13L, 14L, 16L, 18L, 20L, 16L, 18L, 14L, 18L, 14L, 18L, 14L, 15L, 
18L, 20L, 14L, 16L, 14L, 18L, 16L, 16L), e4grp = c("Non-E4", 
"E4", "Non-E4", "Non-E4", "E4", "E4", "E4", "Non-E4", "Non-E4", 
"Non-E4", "E4", "E4", "E4", "Non-E4", "E4", "E4", "Non-E4", "Non-E4", 
"Non-E4", "Non-E4", "Non-E4", "E4", "Non-E4", "E4", "E4", "Non-E4", 
"E4", "Non-E4", "Non-E4", "Non-E4", "Non-E4", "Non-E4", "E4", 
"Non-E4", "E4"), age = c(66L, 71L, 66L, 63L, 71L, 71L, 66L, 65L, 
51L, 53L, 65L, 66L, 75L, 55L, 48L, 52L, 54L, 46L, 54L, 49L, 59L, 
65L, 63L, 66L, 57L, 69L, 57L, 70L, 65L, 60L, 63L, 47L, 46L, 62L, 
57L), mmse = c(30L, 29L, 30L, 29L, 30L, 28L, 29L, 30L, 30L, 30L, 
29L, 29L, 29L, 28L, 29L, 28L, 30L, 30L, 29L, 30L, 30L, 29L, 28L, 
30L, 30L, 29L, 30L, 29L, 29L, 29L, 28L, 30L, 30L, 30L, 29L), 
    ham_d = c(4, 8, 2, 0, 0, 0, 13, 0, 6, 2, 0, 2, 6, 5, 0, 1, 
    2, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, NA, 5, NA
    ), ham_a = c(9, 4, 0, 9, 1, 0, 12, 7, 4, 4, 2, 2, 10, 3, 
    8, 10, 4, 6, 6, 2, 1, 2, 0, 8, 1, 6, 1, 7, 0, 3, 1, 2, NA, 
    10, NA), dig_sym = c(57, 47, 60, 64, 94, 48, 62, 81, 92, 
    66, 52, 55, 40, 74, 88, 63, 57, 88, 99, 86, 72, 53, 67, 77, 
    70, 49, 65, 52, 56, NA, 50, 90, NA, NA, NA), delay_vp = c(8, 
    1, 3, 8, 8, 4, 8, 8, 8, 8, 8, 7, 8, 5, 8, 4, 8, 4, 7, 7, 
    8, 8, 8, 8, 8, 4, 8, 4, 8, NA, 1, 8, NA, NA, 8), bfr_selective_reminding_delayed = c(11, 
    NA, 2, 4, 5, 6, 6, 9, 11, 8, 6, 4, 6, 9, 11, 10, 12, 10, 
    9, 9, 8, 1, 11, 11, 10, 11, 12, 4, 5, NA, 1, 7, 8, 12, 12
    ), sitting = c(10, 11, 5, 7, 3, 5, 4, 6, 7, 10, 15, 2, 6, 
    9, 7, 8, 10, 3, 6, 3, 5, 5, 12, 3, 9, 5, 12, 4, 8, 8, 3, 
    8, 12, 13, 8), met_minwk = c(777, 1039.8, 795, 2400, 2358, 
    693, 495, 1645.8, 396, 742.79999999999995, 2736, 4377, 99, 
    1713, 693, 727.79999999999995, 1971, 2874, 1639.8, 2430, 
    594, 2079, 693, 777, 1230, 684, 1392, 643.79999999999995, 
    5112, 1150.2, 132, 3000, 852, 360, 3942), ipa_qgrp = c("Low", 
    "Low", "Low", "High", "High", "Low", "Low", "High", "Low", 
    "Low", "High", "High", "Low", "High", "Low", "Low", "High", 
    "High", "High", "High", "Low", "High", "Low", "Low", "Low", 
    "Low", "Low", "Low", "High", "Low", "Low", "High", "Low", 
    "Low", "High"), aca1 = c(2.2527499999999998, 2.0882499999999999, 
    2.2096, 1.8206, 1.9690000000000001, 2.05525, 2.2006999999999999, 
    2.1917, 1.9452499999999999, 2.0115500000000002, 2.0979000000000001, 
    2.1471, 2.1732, 1.91995, 2.1207500000000001, 2.1166, 2.0875499999999998, 
    2.1523500000000002, 1.81355, 2.0802999999999998, 2.12235, 
    2.1448999999999998, 2.0899000000000001, 2.1128, 2.0459499999999999, 
    1.9712000000000001, 1.8361499999999999, 1.9604999999999999, 
    1.9692000000000001, 2.1133500000000001, 1.9634, 1.83405, 
    1.83945, 2.0847500000000001, 1.9975000000000001), aca23dg = c(3.3639000000000001, 
    2.9159999999999999, 3.1504500000000002, 2.8603000000000001, 
    3.0667, 2.8908999999999998, 2.8885000000000001, 2.7919499999999999, 
    2.4863, 3.0147499999999998, 2.8679000000000001, 3.1920500000000001, 
    3.0667, 2.6243500000000002, 2.8570500000000001, 3.03335, 
    2.9878499999999999, 2.5882999999999998, 2.6775500000000001, 
    3.4169, 3.1016499999999998, 3.1626500000000002, 2.9851000000000001, 
    3.0283000000000002, 2.9296500000000001, 2.9947499999999998, 
    3.0099, 2.73115, 3.2245499999999998, 2.9430999999999998, 
    2.8595000000000002, 2.7744499999999999, 2.6321500000000002, 
    2.7313499999999999, 2.9328500000000002), ae_cort = c(2.6358000000000001, 
    2.7772999999999999, 2.40835, 2.3029500000000001, 2.7334499999999999, 
    2.4637500000000001, 3.3431000000000002, 2.2465000000000002, 
    2.4019499999999998, 2.48055, 2.2557499999999999, 2.5680499999999999, 
    2.6501999999999999, 2.0293000000000001, 2.6863999999999999, 
    2.6495000000000002, 3.0297000000000001, 2.5581999999999998, 
    2.2132000000000001, 2.6053000000000002, 3.1137999999999999, 
    3.4857499999999999, 2.5758999999999999, 2.7447499999999998, 
    2.5199500000000001, 2.98055, 2.4689000000000001, 2.2353000000000001, 
    3.0318499999999999, 2.2613500000000002, 2.7863500000000001, 
    2.3892000000000002, 2.0851000000000002, 2.2894000000000001, 
    2.25535), a_fusi_cort = c(2.7805499999999999, 2.4982000000000002, 
    2.7616000000000001, 2.4863499999999998, 2.6269999999999998, 
    2.8586, 2.9060999999999999, 2.6292499999999999, 2.6845500000000002, 
    2.65265, 2.54765, 2.6913499999999999, 2.5026000000000002, 
    2.4586999999999999, 2.6730999999999998, 2.8009499999999998, 
    2.8584000000000001, 3.0975999999999999, 2.4449000000000001, 
    2.8247, 2.6650999999999998, 3.0849500000000001, 2.8084500000000001, 
    2.6517499999999998, 2.5501499999999999, 2.5767000000000002, 
    2.7416, 2.5045999999999999, 2.8615499999999998, 2.5541999999999998, 
    2.6281500000000002, 2.40415, 2.3462000000000001, 2.7284999999999999, 
    2.47845), a_ph_cort = c(2.4611000000000001, 3.1350500000000001, 
    3.1763499999999998, 2.6916000000000002, 2.5617000000000001, 
    3.0989, 3.4105500000000002, 2.66805, 2.3409499999999999, 
    2.54495, 2.3853, 2.9436499999999999, 2.5664500000000001, 
    2.1167500000000001, 2.9089499999999999, 3.0005999999999999, 
    3.1296499999999998, 3.1042000000000001, 2.3693499999999998, 
    3.1213500000000001, 3.4885999999999999, 3.8008000000000002, 
    2.6949000000000001, 2.9834000000000001, 2.5827499999999999, 
    2.7122000000000002, 2.6063499999999999, 2.8926500000000002, 
    3.05925, 2.7725499999999998, 2.7644500000000001, 2.4925999999999999, 
    2.3459500000000002, 2.5658500000000002, 2.4244500000000002
    ), a_pe_cort = c(2.6181999999999999, 2.5648499999999999, 
    3.2876500000000002, 2.37405, 2.4975499999999999, 2.5741000000000001, 
    3.2142499999999998, 2.2749999999999999, 2.2576999999999998, 
    2.50935, 2.3776000000000002, 2.2717499999999999, 2.7717499999999999, 
    2.6335000000000002, 2.4680499999999999, 2.85745, 2.8620000000000001, 
    3.01315, 2.2101000000000002, 2.6890999999999998, 2.7612999999999999, 
    3.2730999999999999, 2.82565, 2.8224499999999999, 2.4178999999999999, 
    2.6103499999999999, 2.2941500000000001, 2.7899500000000002, 
    2.6489500000000001, 2.5798000000000001, 2.7074500000000001, 
    2.3578999999999999, 2.339, 2.5089999999999999, 2.1529500000000001
    ), asubic = c(2.5819999999999999, 1.9904999999999999, 1.88995, 
    1.8583499999999999, 2.1513, 2.1741000000000001, 2.3714499999999998, 
    2.0619000000000001, 2.0708000000000002, 1.7419, 2.0803500000000001, 
    2.2848000000000002, 2.1869000000000001, 1.76115, 2.3245499999999999, 
    1.9822, 2.4573, 2.5273500000000002, 1.8610500000000001, 2.2912499999999998, 
    2.1465000000000001, 2.4270499999999999, 1.9833000000000001, 
    2.1680999999999999, 2.0406499999999999, 1.94075, 1.8227, 
    1.9169499999999999, 2.2501000000000002, 1.9131, 2.0383, 2.1228500000000001, 
    2.0259499999999999, 1.9790000000000001, 2.29725), total = c(2.6706099999999999, 
    2.5671599999999999, 2.6977099999999998, 2.3420299999999998, 
    2.5152399999999999, 2.5879400000000001, 2.9049499999999999, 
    2.4091900000000002, 2.3125, 2.4222399999999999, 2.3732099999999998, 
    2.5855399999999999, 2.5596899999999998, 2.2205300000000001, 
    2.5769799999999998, 2.6343800000000002, 2.7732100000000002, 
    2.7201599999999999, 2.2271000000000001, 2.71841, 2.7713299999999998, 
    3.0541700000000001, 2.5661700000000001, 2.6445099999999999, 
    2.4409999999999998, 2.5409299999999999, 2.3971100000000001, 
    2.4330099999999999, 2.72078, 2.44821, 2.5353699999999999, 
    2.3393099999999998, 2.23054, 2.41255, 2.3626900000000002)), row.names = c(NA, 
-35L), class = c("tbl_df", "tbl", "data.frame"))