Case Study: Effects of Lead Exposure on Neurologic and Psychological Function in Children A study was performed to examine the association be- tween lead exposure and developmental features in chil- dren. There are different ways to quantify lead exposure. One method used in the study consisted of a control group of children whose blood-lead levels were < 40 µg/100 mL in both 1972 and 1973 (n = 78) and an exposed group of chil- dren who had blood-lead levels ≥ 40µg/100 mL in either 1972 or 1973 (n = 46) Two important outcome variables in the study were the number of finger-wrist taps per 10 sec- onds in the dominant hand (a measure of neurologic func- tion) as well as the Wechsler full-scale IQ score (a measure of intellectual development). Because only children > 5 years of age were given the neurologic tests, we actually have 35 exposed and 64 control children with finger-wrist tapping scores. From the data set, LEAD.DAT, we note that the exposed group seems to have lower levels than the control group for both these variables. How can we confirm whether this impression is correct?
Please solve using R
LEAD.DOC
VARIABLE COLUMN DESCRIPTION
id 1-3 IDENTIFICATION NUMBER
area 5 AREA - RESIDENCE ON AUG'72
1=0-1 MILES FROM SMELTER
2=1-2.5 MILES
3=2.5-4.1 MILES
ageyrs 7-11 AGE in years xx.xx
sex 13 SEX 1=MALE 2=FEMALE
IQ TEST RESULTS
iqv_inf 15-16 INF - INFORMATION SUBTEST IN WISC AND WPPSI
iqv_comp 18-19 COMP - COMPREHENSION SUBTEST IN WISC AND WPPSI
iqv_ar 21-22 AR - ARITHMETIC SUBTEST IN WISC AND WPPSI
iqv_ds 24-25 DS - DIGIT SPAN SUBTEST(WISC) AND SENTENCE
COMPLETION(WPPSI)
iqv_raw 27-28 V/RAW - RAW SCORE/VERBAL IQ
iqp_pc 30-31 PC - PICTURE COMPLETION SUBTEST IN WISC AND WPPSI
iqp_bd 33-34 BD - BLOCK DESIGN SUBTEST IN WISC AND WPPSI
iqp_oa 36-37 OA - OBJECT ASSEMBLY SUBTEST(WISC), ANIMAL HOUSE
SUBTEST(WPPSI)
iqp_cod 39-40 COD - CODING SUBTEST(WISC), GEOMETRIC DESIGN
SUBTEST(WPPSI)
iqp_raw 42-43 P/RAW - RAW SCORE/PERFORMANCE IQ (TOTAL OF SCORES
PC, BD, OA, & COD)
hh_index 45-46 HH/INDEX - HOLLINGSHEAD INDEX OF SOCIAL STATUS
iqv 48-50 IQV - VERBAL IQ
iqp 52-54 IQP - PERFORMANCE IQ
iqf 56-58 IQF - FULL SCALE IQ (NOT SUM OR AVERAGE OF IQV D IQP)
iq_type 60 TYPE OF IQ TEST 1=WISC 2=WPPSI
(WISC USUALLY GIVEN TO CHILDREN GE 5 YRS 1 MONTH OF AGE
WPPSI USUALLY GIVEN TO CHILDREN LE 5YRS OF AGE)
lead_grp 62 GROUP - BLOOD LEAD LEVEL GROUP
1=BLOOD LEAD LEVELS BELOW 40 MICROGRAMS/100ML IN
BOTH 1972 & 1973 (control group)
2=BLOOD LEAD LEVELS GREATER THAN OR EQUAL TO
40 MICROGRAMS/100ML
IN BOTH 72 & 73 OR A LEVEL GREATER THAN OR
EQUAL TO 40
IN 73 ALONE (3 CASES ONLY) (currently exposed
Group)
3=BLOOD LEAD LEVELS GREATER THAN OR EQUAL TO
40 MICROGRAMS/100ML
IN 72 AND LESS THAN 40 IN 73
(previously exposed group)
Group 64 1=control group; 2=exposed group
ld72 66-67 LD72 - BLOOD LEAD VALUES (MICROGRAMS/100ML) IN72
MISSING=99
ld73 69-70 LD73 - BLOOD LEAD VALUES (MICROGRAMS/100ML) IN 73
fst2yrs 72 FST2YRS - DID CHILD LIVE FOR 1ST 2 YRS WITHIN
1 MILE OF SMELTER 1=YES 2=NO
totyrs 74-75 TOTYRS - TOTAL NUMBER OF YEARS SPENT WITHIN
4.1 MILES OF SMELTER
SYMPTOM DATA (AS REPORTED BY PARENTS)
pica 77 PICA 1=YES 2=NO
colic 79 COLIC 1=YES 2=NO
clumsi 81 CLUMSINESS 1=YES 2=NO
irrit 83 IRRITABILITY 1=YES 2=NO
convul 85 CONVULSIONS 1=YES 2=NO
CONTAIN NEUROLOGICAL TEST DATA
_2plat_r 87-88 # OF TAPS FOR RIGHT HAND IN THE 2-PLATE TAPPING
TEST (#TAPS IN ONE 10 SECOND TRIAL)
MISSING=99
_2plat_l 90-91 # OF TAPS FOR LEFT HAND IN THE 2-PLATE TAPPING TEST
(#TAPS IN ONE 10 SECOND TRIAL)
MISSING=99
visrea_r 93-94 VISUAL REACTION TIME RIGHT HAND (MILLISECONDS)
MISSING=99
visrea_l 96-97 VISUAL REATION TIME LEFT HAND (MILLISECONDS)
MISSING=99
audrea_r 99-100 AUDITORY REACTION TIME RIGHT HAND (MILLISECONDS)
MISSING=99
audrea_l 102-103 AUDITORY REACTION TIME LEFT HAND (MILLISECONDS)
MISSING=99
fwt_r 105-106 FINGER-WRIST TAPPING TEST RIGHT HAND
(# TAPS IN ONE 10 SECOND TRIAL)
MISSING=99
fwt_l 108-109 FINGER-WRIST TAPPING TEST LEFT HAND
(#TAPS IN ONE 10 SECOND TRIAL)
MISSING=99
hyperact 111-112 WWPS - WERRY-WEISS-PETERS SCALE FOR HYPERACTIVITY
0=NO ACTIVITY . . . . 4=SEVERLY HYPERACTIVE
(AS REPORTED BY PARENTS)
MISSING=99
maxfwt 114-115 Finger-wrist tapping test in dominant hand(max of
fwt_r,fwt_l)
Data:
Trending now
This is a popular solution!
Step by step
Solved in 1 steps
