A recent 10-year study conducted by a research team at the Great Falls Medical S

Question

A recent 10-year study conducted by a research team at the Great Falls Medical School was conducted to assess how age, systolic blood pressure, and smoking relate to the risk of strokes. Assume that the following data are from a portion of this study. Risk is interpreted as the probability (times 100) that the patient will have a stroke over the next 10-year period. For the smoking variable, define a dummy variable with 1 indicating a smoker and 0 indicating a nonsmoker.

Risk
Age Systolic
Blood
Pressure
Smoker 12 57 152 No 24 67 163 No 13 58 155 No 56 86 177 Yes 28 59 196 No 51 76 189 Yes 18 56 155 Yes 31 78 120 No 37 80 135 Yes 15 78 98 No 22 71 152 No 36 70 173 Yes 15 67 135 Yes 48 77 209 Yes 15 60 199 No 36 82 119 Yes 8 66 166 No 34 80 125 Yes 3 62 117 No 37 59 207 Yes

Explanation / Answer

Question 1

Here using multiple regression analaysis in excel

where x3 = 0 if no smoker and 1 when if smker

so here regression model is

y^ (Risk) = -91.7595 + 1.0767 * Age + 0.2518 * Systolic Pressure + 8.7399 * Smoker

(b) Here for smoking the p - value is = 0.01, so,at 0.05 significance level it is significant factor.

(c) Here risk

for Age = 69

Blood pressure = 168

Smoker = 1

y^ (Risk) = -91.7595 + 1.0767 * Age + 0.2518 * Systolic Pressure + 8.7399 * Smoker

=  -91.7595 + 1.0767 * 69 + 0.2518 * 168 + 8.7399 * 1

= 33.575

Here the physician might recommend to leave smoking and take care of systolic pressure by doing mild exercises.

(d) Here Probability of stroke < 0.01

so here pressure = 230

smoker = 1

so here

1 >  -91.7595 + 1.0767 * Age + 0.2518 * Systolic Pressure + 8.7399 * Smoker

1 > -91.7595 + 1.0767 * age + 0.2518 * 230 + 8.7399 * 1

1.0767 * age < 1 + 91.7595 - 0.2518 * 230 - 8.7399 = 26.1056

age < 24.25

so the person shall be less than 24 year age

(e) Here factor one can be taken

(ii) obesity too is a factor

(iii Gender is also important

so all of the above

SUMMARY OUTPUT Regression Statistics Multiple R 0.934605 R Square 0.873487 Adjusted R Square 0.849766 Standard Error 5.756575 Observations 20 ANOVA df SS MS F Significance F Regression 3 3660.74 1220.247 36.82301 2.06E-07 Residual 16 530.2104 33.13815 Total 19 4190.95 Coefficients Standard Error t Stat P-value Lower 95% Upper 95% Lower 95.0% Upper 95.0% Intercept -91.7595 15.22276 -6.02778 1.76E-05 -124.03 -59.4887 -124.03 -59.4887 Age 1.076741 0.165964 6.487814 7.49E-06 0.724914 1.428568 0.724914 1.428568 Systolic Pressure 0.251813 0.045226 5.567951 4.24E-05 0.15594 0.347687 0.15594 0.347687 Smoker 8.739871 3.000815 2.912499 0.010174 2.378427 15.10132 2.378427 15.10132

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.