The following originally appeared on The Upshot (copyright 2017, The New York Times Company).
Your speed of recovery in a hospital is related to many things. Among them is one you might not consider: the condition of your roommate.
A recent study published in the American Journal of Health Economics found that hospital patients who are assigned healthier roommates require less care and are discharged more rapidly, with no negative effects on their health. For example, a patient who rooms with the healthiest roommate has a hospital stay that is about eight hours shorter, requiring 27 percent less medical attention, and costing about $840 less, compared with a patient with the sickest roommate. Female patients with healthier roommates are discharged in better condition and have a smaller chance of requiring re-hospitalization.
The study examined a broad range of hospital patients, including those who had surgical procedures — like heart bypasses or joint replacement operations — as well as those admitted for medical conditions like pneumonia or cancer.
At first glance, there is an apparently obvious explanation for these findings: Patients are typically assigned to room with other patients of similar condition. In particular, healthier people are assigned to rooms farther from the nursing station. Therefore, healthier patients — those who require less care and are discharged more rapidly — also tend to room with relatively healthier patients. So there seems to be a noncausal connection between the recovery speed of patients and the health of their roommates.
But the author of the study, Olga Yakusheva, a University of Michigan economist, controlled for the factors that nurses at the Connecticut hospital she studied use to assign patients to rooms, including diagnosis and specific room assignment. She found that even in a particular room at the hospital and even among patients with a specific diagnosis, those who ended up with healthier roommates fared better. (The study did not include patients who had single rooms.)
What’s more, “placing a sick and a healthy patient in one room benefited the sicker patient without ill effects for the healthier roommate,” Ms. Yakusheva said.
Had that particular hospital taken fuller advantage of this phenomenon in patient room assignments, it could have reduced total inpatient days by 900 per year, saving about $1 million, for the sample of patients the study examined.
In recent years, most American hospitals have gone another way, though. They’ve added private rooms and renovated shared ones to accommodate only one person. The amount of hospital room space per patient has doubled since the late 1980s. Naturally, that increases costs.
Many patients prefer the privacy of a single room. And some studies indicate that single rooms reduce the spread of flu and other infections, though the evidence is not conclusive. Despite the potential risks and preferences, having a hospital roommate, and a healthier one in particular, may be better than having no roommate.
There are several hypotheses for how roommate assignments affect patients’ health. A healthier roommate — particularly one with a similar condition — may be better able to transfer important self-care knowledge or even lend a helping hand, as a few studies have documented. Or, patients with healthier roommates may feel better when they observe other patients doing well, relative to those who observe patients doing poorly. Some studies have found that patient interactions can reduce anxiety.
Other possibilities are indirect. If your roommate is healthier, she may draw on fewer nursing resources (time and attention), leaving more for you. Or, you may be better able to rest because nurses and doctors are entering the room less frequently when your roommate needs less care. Additional analysis by Ms. Yakusheva doesn’t support these indirect explanations, however.
The phenomenon is just one of many “peer effects” — the tendency for certain behaviors to spread through social interaction — that have been identified and studied by researchers. It’s probably no surprise that the nature of your social engagement with friends, family and colleagues influences your degree of cooperation and happiness, as studies have found. Research also suggests that it affects behaviors more closely tied to health. For example, obesity tends to spread in social networks. So does smoking behavior. Alcohol consumption follows similar patterns.
Even if it’s plausible that healthier roommates improve hospital patients’ outcomes, we should acknowledge some limitations of the research in this area. There are very few studies of the subject beyond Ms. Yakusheva’s. Hers is a study of one hospital, with a sample that may not be representative of all hospital patients. Also, as with all observational studies (as opposed to randomized trials), there may be other important influences that could not be accounted for that affect the results.
If there is a positive efect, of what use are the findings? If you’re hospitalized, could you increase your chances of being assigned to a room with a healthier roommate? The answer, according to Bradley Flansbaum, a hospitalist with the Geisinger Health System, is yes.
“You could always ask the nurse in charge for a room change,” he said. “If asked why, and you say it’s for personal reasons, the nurse will probably accommodate.”
But this might put too much onus on the patient, and there is no guarantee the new roommate will be any healthier. A better approach might be for hospital staff to systematically take the phenomenon into account when assigning patients to rooms.