load hospital
y = hospital.BloodPressure(:,1);
X = double(hospital(:,2:5));
X2 = X(:,3);
mdl = fitlm(X2,y);

Estimated Coefficients:
                   Estimate       SE       tStat       pValue
                   ________    ________    ______    __________

    (Intercept)      116.72      3.9389    29.633    1.0298e-50
    x1             0.039357    0.025208    1.5613       0.12168


Number of observations: 100, Error degrees of freedom: 98
Root Mean Squared Error: 6.66
R-squared: 0.0243,  Adjusted R-Squared 0.0143
F-statistic vs. constant model: 2.44, p-value = 0.122