The respiratory rate indicates the rate at which the person takes breaths. 18-20 is considered normal. Tachypnea (abnormally elevated respiratory rate) is seen commonly in clinical practice and indicates an oxygen shortage in the body, usually due to either a cardiac or pulmonary cause. Bradypnea is an abnormally low respiratory rate.

In the following code, we convert the RESPR variable to a numeric type and then perform a mean imputation of the missing values:

X_train.loc[:,'RESPR'] = X_train.loc[:,'RESPR'].apply(pd.to_numeric)
X_test.loc[:,'RESPR'] = X_test.loc[:,'RESPR'].apply(pd.to_numeric)

X_train = mean_impute_values(X_train,'RESPR')
X_test = mean_impute_values(X_test,'RESPR')