The effect of sunlight on postoperative analgesic medication use: a prospective study of patients undergoing spinal surgery

Exposure to natural sunlight has been associated with improvement in mood, reduced mortality among patients with cancer, and reduced length of hospitalization for patients who have experienced myocardial infarction. Our aim was to evaluate whether the amount of sunlight in a hospital room modifies a patient's psychosocial health, the quantity of analgesic medication used, and the pain medication cost. A prospective study of pain medication use was conducted in 89 patients undergoing elective cervical and lumbar spinal surgery where they were housed on either the "bright" or "dim" side of the same hospital unit. Analgesic medication was converted to standard morphine equivalents for interpatient comparison. The intensity of sunlight in each hospital room was measured daily and psychologic questionnaires were administered on the day after surgery and at discharge. Patients staying on the bright side of the hospital unit were exposed to 46% higher-intensity sunlight on average (p = .005). Patients exposed to an increased intensity of sunlight experienced less perceived stress (p = .035), marginally less pain (p = .058), took 22% less analgesic medication per hour (p = .047), and had 21% less pain medication costs (p = .047). Age quartile was the only other variable found to be a predictor of analgesic use, with a significant negative correlation (p