A 45-year-old woman comes to the physician because of fatigue and irregular menstrual cycles for the past year. She also complains of recurrent sinus infections. During the past 6 months, she has had increased urinary frequency and swelling of her feet. She has also had difficulty lifting her 3-year-old niece for the past 3 weeks. She was recently diagnosed with depression. She works as a medical assistant. The patient has smoked one half-pack of cigarettes daily for 25 years and drinks four beers on the weekends. Her only medication is escitalopram. She is 160 cm (5 ft 3 in) tall and weighs 79 kg (175 lb); BMI is 31 kg/m2. She appears tired. Her temperature is 37°C (98.6°F), pulse is 80/min, respirations are 18/min, and blood pressure is 140/82 mm Hg. Physical examinations shows neck obesity and an enlarged abdomen. Examination of the skin shows multiple bruises on her arms and legs. There is generalized weakness and atrophy of the proximal muscles. Laboratory studies show:
Serum
Na+ 150 mEq/L
K+ 3.0 mEq/L
Cl- 103 mEq/L
HCO3- 30 mEq/L
Urea nitrogen 19 mg/dL
Creatinine 0.9 mg/dL
Glucose 136 mg/dL
A 1 mg overnight dexamethasone suppression test shows a serum cortisol of 167 nmol/L (N < 50) and a 24-hour urinary cortisol is 425 μg (N < 300 μg). Serum ACTH is 169 pg/mL (N = 7–50). Subsequently, a high-dose dexamethasone suppression test shows a serum cortisol level of 164 nmol/L (N < 50).
The formula for computing Cockcroft-Gault is given by CrCl = ((140 - age) * adjusted weight * (gender_coefficient)) / (serum creatinine * 72), where the gender_coefficient is 1 if male, and 0.85 if female. The serum creatinine concentration is in mg/dL.
The patient's gender is female, which means that the gender coefficient is 0.85.
The patient is 45 years old. 
The concentration of creatinine is 0.9 mg/dL. 
The formula for computing the patient's BMI is (weight)/(height * height), where weight is the patient's weight in kg and height is the patient's height in m.
The patient's height is 160.0 cm, which is 160.0 cm * 1 m / 100 cm = 1.6 m. The patient's weight is 79.0 kg. The patient's bmi is therefore 79.0 kg / (1.6 m * 1.6 m) = 30.859 kg/m^2.The patient's BMI is 30.9, indicating they are overweight/obese.
Because the patient is overweight/obese, we use the adjusted body weight formula to get the adjusted weight used for Cockroft-Gault Equation. Shown below is the computation for IBW (ideal body weight).
The patient's gender is Female.
The patient's height is 160.0 cm, which is 160.0 cm * 0.393701 in/cm = 62.992 in. 
For females, the ideal body weight (IBW) is calculated as follows:
IBW = 45.5 kg + 2.3 kg * (height (in inches) - 60)
Plugging in the values gives us 45.5 kg + 2.3 kg * (62.992 (in inches) - 60) = 52.382 kg.
Hence, the patient's IBW is 52.382 kg.Shown below is the computation for ABW (adjusted body weight).
To compute the ABW value, apply the following formula: ABW = IBW + 0.4 * (weight (in kg) - IBW (in kg)). ABW = 52.382 kg + 0.4 * (79.0 kg  - 52.382 kg) = 63.029 kg. The patient's adjusted body weight is 63.029 kg.

Using the Cockcroft-Gault equation:
CrCl = ((140 - age) * adjusted weight * gender_coefficient) / (serum creatinine * 72).
Plugging the patient's values gives us ((140 - 45) * 63.029 * 0.85) / (0.9 * 72) = 78.543 mL/min. Hence, the patient's creatinine clearance is 78.543 mL/min.