Birthweight analysis
Read data
dat <- read.csv("Birthweight.csv")dat## id headcirumference length Birthweight Gestation smoker motherage mnocig
## 1 1313 12 17 5.8 33 0 24 0
## 2 431 12 19 4.2 33 1 20 7
## 3 808 13 19 6.4 34 0 26 0
## 4 300 12 18 4.5 35 1 41 7
## 5 516 13 18 5.8 35 1 20 35
## 6 321 13 19 6.8 37 0 28 0
## 7 1363 12 19 5.2 37 1 20 7
## 8 575 12 19 6.1 37 1 19 7
## 9 822 13 19 7.5 38 0 20 0
## 10 1081 14 21 8.0 38 0 18 0
## 11 1636 14 20 8.6 38 0 29 0
## 12 1107 14 20 7.1 38 0 31 0
## 13 1023 13 20 6.6 38 1 30 12
## 14 1369 13 19 7.0 38 1 31 25
## 15 697 13 19 6.6 39 0 27 0
## 16 1600 13 21 6.3 39 0 19 0
## 17 57 14 20 7.3 39 1 23 17
## 18 272 14 20 8.5 39 1 30 25
## 19 569 13 19 5.5 39 1 22 7
## 20 619 13 20 7.5 39 1 23 25
## 21 1522 13 19 6.0 39 1 21 17
## 22 820 13 20 8.3 40 0 24 0
## 23 1016 14 21 9.5 40 0 19 0
## 24 1058 13 20 6.9 40 0 29 0
## 25 1088 14 20 7.2 40 0 24 0
## 26 365 14 20 7.7 40 1 26 25
## 27 532 13 21 7.9 40 1 31 12
## 28 752 14 19 7.3 40 1 27 12
## 29 792 14 21 8.0 40 1 20 2
## 30 1272 12 20 6.0 40 1 37 50
## 31 462 15 22 9.0 41 0 35 0
## 32 755 13 21 7.0 41 0 21 0
## 33 1683 13 21 7.3 41 0 27 0
## 34 27 14 20 7.8 41 1 37 25
## 35 1262 13 21 7.0 41 1 27 35
## 36 1388 13 20 6.9 41 1 22 7
## 37 1764 15 22 10.0 41 1 32 12
## 38 553 14 21 8.6 42 0 24 0
## 39 1191 13 21 8.0 42 0 21 0
## 40 1360 13 22 10.0 44 0 20 0
## 41 223 13 19 8.5 45 1 28 25
## 42 1187 14 20 8.9 44 0 20 0
## mheight mppwt fage fedyrs fnocig fheight lowbwt mage35 LowBirthWeight
## 1 58 99 26 16 0 66 1 0 Low
## 2 63 109 20 10 35 71 1 0 Low
## 3 65 140 25 12 25 69 0 0 Normal
## 4 65 125 37 14 25 68 1 1 Low
## 5 67 125 23 12 50 73 1 0 Low
## 6 62 118 39 10 0 67 0 0 Normal
## 7 64 104 20 10 35 73 1 0 Low
## 8 65 132 20 14 0 72 0 0 Normal
## 9 62 103 22 14 0 70 0 0 Normal
## 10 67 109 20 12 7 67 0 0 Normal
## 11 64 135 31 16 0 70 0 0 Normal
## 12 64 125 35 16 0 72 0 0 Normal
## 13 64 140 38 14 50 70 0 0 Normal
## 14 63 124 32 16 50 76 0 0 Normal
## 15 63 135 27 14 0 70 0 0 Normal
## 16 64 125 23 14 2 76 0 0 Normal
## 17 62 104 32 12 25 66 0 0 Normal
## 18 67 170 40 16 50 70 0 0 Normal
## 19 62 115 23 14 25 78 1 0 Low
## 20 71 152 23 16 2 71 0 0 Normal
## 21 61 115 24 12 7 70 0 0 Normal
## 22 62 110 31 16 0 68 0 0 Normal
## 23 67 135 19 12 0 72 0 0 Normal
## 24 65 130 30 16 25 71 0 0 Normal
## 25 66 117 29 16 0 71 0 0 Normal
## 26 67 137 30 10 25 71 0 0 Normal
## 27 64 107 41 12 50 75 0 0 Normal
## 28 60 105 37 12 25 66 0 0 Normal
## 29 66 130 24 12 12 73 0 0 Normal
## 30 66 135 31 16 0 68 0 1 Normal
## 31 67 127 31 16 25 73 0 1 Normal
## 32 61 120 25 14 25 72 0 0 Normal
## 33 64 135 37 14 0 66 0 0 Normal
## 34 63 145 46 16 0 68 0 1 Normal
## 35 64 110 31 16 25 72 0 0 Normal
## 36 63 117 24 16 12 69 0 0 Normal
## 37 68 154 38 14 25 71 0 0 Normal
## 38 69 143 30 12 0 72 0 0 Normal
## 39 65 132 21 10 25 73 0 0 Normal
## 40 63 125 23 10 35 70 0 0 Normal
## 41 64 118 30 16 0 72 0 0 Normal
## 42 68 150 26 14 25 74 0 0 NormalDo smokers have lighter babies?
dat %>%
ggplot(aes(x=factor(smoker), y=Birthweight)) +
geom_boxplot()
dat %>%
group_by(smoker) %>%
summarise(mean_birthweight = mean(Birthweight),
median_birthweight = median(Birthweight))## # A tibble: 2 × 3
## smoker mean_birthweight median_birthweight
## <int> <dbl> <dbl>
## 1 0 7.69 7.4
## 2 1 6.88 7Is there a relationship between low birth weight & mother’s age over 35 yrs?
dat %>%
ggplot(aes(x=factor(mage35),fill=LowBirthWeight)) +
geom_bar(position = "fill")
dat %>%
count(mage35, LowBirthWeight)## mage35 LowBirthWeight n
## 1 0 Low 5
## 2 0 Normal 33
## 3 1 Low 1
## 4 1 Normal 3risk_under35 = 5/(5+33)
risk_over35 = 1/(1+3)
relative_risk = risk_over35/risk_under35
relative_risk## [1] 1.9Father’s height related to mother’s height?
dat %>%
ggplot(aes(x=mheight,y=fheight,col=LowBirthWeight)) +
geom_point()
cor(dat$mheight, dat$fheight)## [1] 0.272824