The risk of developing heart failure within 4 years can be predicted using regression equations based on data in the Framingham Study.
Patients:
(1) both men and women
(2) adults aged 45 to 94
X =
= SUM((variable value) * (regression coefficient))
probability of developing heart failure within 4 years =
= 1 / (1 = EXP((-1) * (X)))
|
Variable for Males Table 1 |
Units |
Regression Coefficient |
|---|---|---|
|
intercept |
|
-7.3611 |
|
age in years |
10 years |
0.0313 |
|
left ventricular hypertrophy |
yes/no |
0.8428 |
|
vital capacity |
100 cL |
-0.0030 |
|
heart rate |
10 bpm |
0.0144 |
|
systolic blood pressure |
20 mm Hg |
0.0067 |
|
CHD |
yes/no |
1.5333 |
|
valvular disease |
yes/no |
0.8868 |
|
diabetes |
yes/no |
0.2383 |
|
cardiomegaly |
yes/no |
0.7968 |
from Table 2, page 1199
where:
• CHD is expanded as congenital heart disease in the legend to the tables, but coronary heart disease seems to be more consistent with the article content.
• cL for vital capacity is interpreted as centiliters
• Left ventricular hypertrophy is based on ECG changes, while a chest radiograph can be used to report cardiomegaly.
• I am a bit confused by the units for age, vital capacity, heart rate and systolic blood pressure. The example calculation given on page 1199 indicates that the patient values for age (in years), vital capacity (in centiliters), blood pressure (in mm Hg) and heart rate (bpm) are used in the calculation, without adjustment to the units listed.
• The presence of a murmur may be used as evidence of valvular disease.
• Table 1 for males and females include vital capacity and chest X-ray (for cardiomegaly), which may not be available in all ambulatory care encounters.
|
Variable for Males Table 2 |
Units |
Regression Coefficient |
|---|---|---|
|
intercept |
|
-9.2087 |
|
age in years |
10 years |
0.0412 |
|
left ventricular hypertrophy |
yes/no |
0.9026 |
|
heart rate |
10 bpm |
0.0166 |
|
systolic blood pressure |
20 mm Hg |
0.00804 |
|
CHD |
yes/no |
1.6079 |
|
valvular disease |
yes/no |
0.9714 |
|
diabetes |
yes/no |
0.2244 |
from Table 3, page 1200
|
Variable for Females Table 1 |
Units |
Regression Coefficient |
|---|---|---|
|
intercept |
|
-5.4997 |
|
age in years |
10 years |
0.0216 |
|
left ventricular hypertrophy |
yes/no |
1.0072 |
|
vital capacity |
100 cL |
-0.0087 |
|
heart rate |
10 bpm |
0.0092 |
|
systolic blood pressure |
20 mm Hg |
0.0032 |
|
CHD |
yes/no |
1.5358 |
|
valvular disease |
yes/no |
1.2454 |
|
diabetes |
yes/no |
1.4275 |
|
cardiomegaly |
yes/no |
0.4792 |
|
valve disease and diabetes |
yes/no |
-0.9292 |
from Table 2, page 1199
|
Variable for Females Table 2 |
Units |
Regression Coefficient |
|---|---|---|
|
intercept |
|
-10.7988 |
|
age in years |
10 years |
0.0503 |
|
left ventricular hypertrophy |
yes/no |
1.3402 |
|
heart rate |
10 bpm |
0.0105 |
|
systolic blood pressure |
20 mm Hg |
0.00337 |
|
CHD |
yes/no |
1.5549 |
|
valvular disease |
yes/no |
1.3929 |
|
diabetes |
yes/no |
1.3857 |
|
body mass index (BMI) |
yes/no (see note) |
0.0578 |
|
valve disease and diabetes |
yes/no |
-0.9860 |
from Table 3, page 1200
where:
• I am not sure how the body mass index can be reported as yes/no. I have used the calculated BMI value in the spreadsheet.
Specialty: Cardiology
ICD-10: ,
