Weather conditions and spinal patients.

STUDY DESIGN: A retrospective study. OBJECTIVES: To evaluate the effects of various weather conditions on reported health status. SUMMARY OF BACKGROUND DATA: Existing literature shows no definite conclusions regarding the effect of weather on patients with spinal pathology. METHODS: Initial visit data from 23 American centers participating in the National Spine Network included demographic information and SF-36-based health status. Weather conditions when and where patients were seen were obtained from the National Climatic Data Center and U.S. Naval Observatory. SF-36 outcomes were predicted using multiple regression techniques from weather parameters, which included high and low temperature, average dew point, wet bulb, barometric pressure, total precipitation, phase of the moon, and length of sunlight. RESULTS: A total of 26,862 of 54,062 patients were identified. Two models were compared: model 1 included the above weather predictors and model 2 added age and gender. For each SF-36 scale and subscale and the Physical and Mental composite Scores, both models were statistically significant, although only model 2 for physical function produced an R value greater than 1%. Barometric pressure was the only weather predictor that was consistently significant. Increased pressure was associated with worse outcomes. Although age and gender were significant additions to the prediction equation, overall, the practical contribution was minimal. CONCLUSION: A statistically significant relationship between weather factors and SF-36-based health status exists but has minimal clinical significance. These factors had minimal if any effect on mental health-related scores bringing into question either the relationship between weather and psychological status, at least in patients with spinal problems or the usefulness of the instrument used.