Table 3 Nineteen if-then rules extracted from the decision tree in Fig. 3

Rule 1: IF age ≤ 49, without a family history of diabetes, BMI ≤ 25, THEN patient is normal (1457/1466 or 99%)

Rule 2: IF age ≤ 34, without a family history of diabetes, BMI > 25, prefers salty food, THEN patient is normal (136/143 or 95%)

Rule 3: IF 35 < age ≤ 49, without a family history of diabetes, BMI > 25, prefers salty food, without physical activity, THEN patient is diabetic (40/44 or 91%)

Rule 4: IF 35 < age ≤ 49, without a family history of diabetes, BMI > 25, prefers salty food, with physical activity, without history of cardiovascular disease or stroke, THEN patient is normal (41/44 or 93%)

Rule 5: IF 35 < age ≤ 49, without a family history of diabetes, BMI > 25, prefers salty food, with physical activity, with history of cardiovascular disease or stroke, THEN patient is diabetic (3/4 or 75%)

Rule 6: IF age ≤ 49, without a family history of diabetes, BMI > 25, without preference for salty food, THEN patient is normal (265/272 or 97%)

Rule 7: IF age ≤ 49, with a family history of diabetes, BMI ≤ 25, THEN patient is normal (215/231 or 93%)

Rule 8: IF age ≤ 49, with a family history of diabetes, BMI > 25, THEN patient is diabetic (98/101 or 97%)

Rule 9: IF age > 49, with work stress high, without a family history of diabetes, BMI ≤ 25, THEN patient is normal (15/16 or 94%)

Rule 10: IF age > 49, with work stress high, without a family history of diabetes, BMI > 25, THEN patient is diabetic (9/11 or 82%)

Rule 11: IF age > 49, with work stress high, with a family history of diabetes, THEN patient is diabetic (85 or 100%)

Rule 12: IF age > 49, with work stress low or moderate, BMI > 25, without a family history of diabetes, prefers salty food, THEN patient is diabetic (45/53 or 85%)

Rule 13: IF age > 49, with work stress low or moderate, BMI > 25, without a family history of diabetes, without preference for salty food, THEN patient is normal (72/88 or 82%)

Rule 14: IF age > 49, without work stress high, BMI > 25, with a family history of diabetes, THEN patient is diabetic (51 or 100%)

Rule 15: IF age > 49, with work stress low or moderate, BMI ≤ 25, prefers salty food, with hypertension, with work stress, THEN patient is diabetic (47/59 or 80%)

Rule 16: IF age > 49, with work stress low or moderate, BMI ≤ 25, prefers salty food, without hypertension, gender male, with history of cardiovascular disease or stroke, THEN patient is diabetic (23/28 or 82%)

Rule 17: IF age > 49, with work stress low or moderate, BMI ≤ 25, prefers salty food, without hypertension, gender male, without history of cardiovascular disease or stroke, THEN patient is normal (6/7 or 86%)

Rule 18: IF age > 49, with work stress low or moderate, BMI ≤ 25, prefers salty food, without hypertension, gender female, THEN patient is normal (78/103 or 76%)

Rule 19: IF age > 49, with work stress low or moderate, BMI ≤ 25, without preference for salty food, THEN patient is normal (216/246 or 88%)