The Study of Osteoporotic Fractures dataset posted on the NSRR was prepared by the dataset owners at SOF Online. Changes and updates to the source data and variable definitions have been coordinated in the sof-data-dictionary repository.
The dataset contains 461 records. Records can be linked to raw polysomnography data by using the sofid subject identifier.
SOF is a longitudinal project with many visits. The polysomnography data were collected at Visit 8 (2002-2004). The NSRR team selected other variables to include from SOF Online, some of which come from other visits. Please note variable prefixes (e.g. v1 for Visit 1, v4 for Visit 4, etc.) when using the SOF dataset, given that some variables were collected at different visits (i.e. many years apart).