## Cancer rates: Part 2, does alcohol consumption have incremental predictive power?

Same guy proposed another idea. Wikipedia has data here. However, since i had previously seen that people fudge data on Wikipedia articles (e.g. this one), then maybe it was not a good idea to just rely on Wikipedia. So i did the best thing: fetched both the data from Wiki and the data from the primary source (WHO), and then compared them for accuracy. They were 100 identical for the “total rates”. I did not compare the other variables. But at least this dataset was not fudged. :)

So, then i loaded the data in R and plotted alcohol consumption per capita (age >=15) vs. cancer rates per capita.

source(“merger.R”) #load custom functions

short.names = as.abbrev(rownames(alcohol)) #gets the abbreviated names so it can be merged with megadataset
rownames(alcohol) = short.names #inserts the abbreviated names

DF.mega2= merge.datasets(alcohol,DF.mega) #merge datasets

scatterplot(CancerRatePer100000 ~ AlcoholConsumptionPerCapitaWHO, DF.mega2, #plot it
smoother=FALSE, #no moving average
labels = rownames(DF.mega),id.n=nrow(DF.mega)) #include datapoint names

There is no relationship there. However, it may work in multiple regression:

lm1 = lm(CancerRatePer100000 ~ AlcoholConsumptionPerCapitaWHO+X2012LifeExpectancyatBirth,
DF.mega2)
summary(lm1)

```Call:
lm(formula = CancerRatePer100000 ~ AlcoholConsumptionPerCapitaWHO +
X2012LifeExpectancyatBirth, data = DF.mega2)

Residuals:
Min      1Q  Median      3Q     Max
-48.677 -26.569   0.717  28.486  61.631

Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept)                    -91.6149    79.2375  -1.156    0.254
AlcoholConsumptionPerCapitaWHO   1.7712     1.6978   1.043    0.303
X2012LifeExpectancyatBirth       4.2518     0.9571   4.442 6.13e-05 ***
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

Residual standard error: 31.56 on 43 degrees of freedom
(227 observations deleted due to missingness)
Multiple R-squared:  0.3158,	Adjusted R-squared:  0.284
F-statistic: 9.923 on 2 and 43 DF,  p-value: 0.0002861```

There is seemingly no predictive power of alcohol consumption! But it does cause cancer, right? According to my skim of Wiki, yes, but only 3.5% of cancer cases, so the effect is too small to be seen here.

The data is in megadataset 1.7c.