The hedonic treadmill is a concept that people acclimate to changes in their life and improvements in quality of life. For instance, people who buy a new car have a brief short-term burst of happiness, but after people acclimate to having the car, their quality of life returns to the previous level. This concept can be true of most new purchases (e.g., clothes, technology, housing) in the developed world. Going from lacking shelter or food are a few of the exceptions where material gains affect quality of life for a sustained period.
One question is whether this concept works in reverse with respect to health. In other words, when previously healthy individuals have a new disease or ailment, do they eventually acclimate to their new quality of life and return to the status quo quality of life?
Some previous research indicates that patients “tend to self‐ report better subjective health over the disease trajectory, even if more objective health measures suggest that their condition is not improving.” Additionally, patient reference points may change when a person has a disease. For instance, in some clinical trials for cancer treatments, the patient subjective quality of life among cancer patients who had recently come off treatment and were progression-free was higher than for healthy individuals in the general public.
Cubí‐Mollá, Jofre‐Bonet, and Serra‐Sastre (2017) examine these questions in more detail. The authors analyzed the issue of adaptation by estimating the effect of the presence of a long‐ standing illness and the time since diagnosis on the construct of subjective self‐ assessed health. The authors use data from the the British Cohort Study (BCS70), a longitudinal survey dataset of 17,287 individuals born in 1970 in England, Wales, and Scotland that captures patient measures of quality of life. The surveys were administered when the individuals were aged 5, 10, 16, 26, 30, 34, 38, and 42. The authors measure changes in self-assessed health (Excellent, Good, Fair or Poor) as a function of the duration one of the long-standing illnesses studied. The long-standing illnesses include: diabetes; depression; anxiety; epilepsy; high blood pressure (HBP); migraine; hay fever, rhinitis, and other diseases of the upper respiratory tract (URT); asthma; cancer; ulcer; Crohn’s disease; eczema; psoriasis; and back problems.
Using this approach, the author find that:
Despite the negative impact of suffering from an LSI, individuals are likely to report better health states the longer they experience a chronic condition. In particular, the APEs [average partial effects] for each of the SAH [subjective assessment of health] categories reveal that differences in the effect of the morbidity and duration variables arise between excellent and all other SAH categories (good, fair , and poor ). Suffering from a chronic illness decreases the likelihood of reporting excellent health, but longer durations counterbalance this effect; that is, duration increases the probability of reporting SAH as excellent.
- Cubí‐Mollá, Patricia, Mireia Jofre‐Bonet, and Victoria Serra‐Sastre. “Adaptation to health states: Sick yet better off?” Health Economics (2017).