A 35-year-old man comes to the emergency department due to 2 days of fever and dysuria. He has a history of paraplegia as the result of a gunshot wound 5 years ago that required surgical intervention. He takes narcotics for chronic pain that has developed since the surgery. The patient is bedbound and practices intermittent urinary self-catheterization. He has had multiple admissions for recurrent urinary tract infections; urine cultures have grown multidrug-resistant organisms requiring intravenous antibiotic therapy in the past. He most recently completed a course of antibiotics a week ago. The patient says, "It feels like my urinary tract infection is coming back-I was just done with antibiotics and was hoping I would get a break!" He reports that every 5 years of life in his current state of health are equivalent to 1 year of life in full health. Which of the following measures is best described by this value?

Question

A 35-year-old man comes to the emergency department due to 2 days of fever and dysuria.  He has a history of paraplegia as the result of a gunshot wound 5 years ago that required surgical intervention.  He takes narcotics for chronic pain that has developed since the surgery.  The patient is bedbound and practices intermittent urinary self-catheterization.  He has had multiple admissions for recurrent urinary tract infections; urine cultures have grown multidrug-resistant organisms requiring intravenous antibiotic therapy in the past.  He most recently completed a course of antibiotics a week ago.  The patient says, "It feels like my urinary tract infection is coming back-I was just done with antibiotics and was hoping I would get a break!"  He reports that every 5 years of life in his current state of health are equivalent to 1 year of life in full health.  Which of the following measures is best described by this value?

Quizplus · Accepted Answer

Explanation: For this patient, 5 years in his current state are equivalent to 1 year of full health; therefore, his time-trade-off (TTO) = 1/5 = 0.20. TTOs are used to calculate quality-adjusted life years (QALYs). QALYs, along with disability-adjusted life years (DALYs), are burden of disease measures evaluating the impact of specific diagnoses/treatments on individual patients or the economic impact of health interventions on populations. For individual QALY calculations, full health has a weight of 1, whereas a disability has a TTO between 0 and 1, depending on the individual. For a patient with a disability who estimates that 5 "limited years" (with the disability) are equivalent to 1 "healthy year," each "limited year" contributes a TTO = 1/5 = 0.20 years to QALYs. A patient who had full health until age 30 (weight = 1), then developed a disability with a TTO = 0.20, will have the following QALYs at age 35 (ie, given 35 - 30 = 5 years with the disability): QALYs = (30 × 1) + (5 × 0.20) = 30 + 1 = 31 QALYs should be maximized through interventions that increase TTO. DALYs represent a loss to be minimized. They reflect the difference between the current situation and an ideal situation (living in perfect health up to the standard life expectancy age) and are commonly used in global burden of disease comparisons (Choice A). DALYs = YLL + YLD Where: YLL = years of life lost due to premature mortality (Choice E). For individuals, YLL is based on standard tables of life expectancy based on age. YLD = years lived with disability, with a standard disability weight for the disability (which, unlike TTO, is based on averages of populations rather than on individual preferences) (Choices C and D). For a woman who develops moderate depression at age 30 and commits suicide at age 50, if standard life expectancy at age 50 is 84 and disability weight for moderate depression is 0.35, then: YLL = 84 - 50 = 34 (years lost compared to standard life expectancy at age 50) YLD = (30 × 0) + (20 × 0.35) = 0 + 7 = 7, reflecting 30 years with no disability (30 × 0) and 20 years (= 50 - 30) with disability weight = 0.35 DALYs = YLL + YLD = 34 + 7 = 41 years lost due to disability and premature mortality. Interventions should aim to minimize this number. Formulas (included for completion) differ for populations and should not be memorized. Educational objective: Quality-adjusted life years (QALYs) and disability-adjusted life years (DALYs) measure burden of disease for individuals or populations. Time-trade-off is commonly used for QALY calculations; years of life lost and years lived with disability are used for DALY calculations. References: Health outcomes in economic evaluation: the QALY and utilities (http://www.ncbi.nlm.nih.gov/pubmed/21037243)

A 35-Year-Old Man Comes to the Emergency Department Due to 2