Thank you for the swift and informative reply! The missing values in slp_eff make more sense now, and my team will end up using this variable. We just came up with some questions that aren't relevant to sleep efficiency, but since I'm already here...
Is there any information about retirement/career status? I was unable to find it in the dictionary.
We're also interested in grouping by date, if possible. The variable representing the "date questionnaire was completed (days from index date)" (https://sleepdata.org/datasets/shhs/variables/date10) seems like a good starting point, but what does "index date" mean and where can it be found?
I have a few questions regarding SHHS1 data:
Is there a good way to get subjective sleep efficiency (SE)? From the morning survey, I was thinking of using hwlghr10 & hwlgmn10 (how long slept in hrs/minutes) as total subjective sleep time, then adding minfa10 (minutes to fall asleep) to get the subjective time in bed, but I don't know how to get subjective time awake during the night. Thoughts?
There is data available for objective SE calculated from PSG: https://sleepdata.org/datasets/shhs/variables/slp_eff, but there were many missing values in the actual dataset for this variable. I noticed there's also a measure explicitly marked "PSG Report (SHHS2): Sleep Efficiency:" https://sleepdata.org/datasets/shhs/variables/slpeffp, but this is also in the SHHS1 dataset. The slpeffp values match existing slp_eff values as well as the missing values of slp_eff (100*SlpPrdP/TimeBedP, when slp_eff is blank for some reason). So, what's the difference between slp_eff and slpeffp, and is it all right to use the latter for SHHS1?
Any answers or guidance would be appreciated! Thanks,