Tracking health conditions
I am currently working with the harmonised BHPS/US data and looking to chart various health conditions. For example in the BHPS waves variable hlprbh identifies if the respondent has diabetes and this grows from just under 2% in wave 1 until about 5% in wave 18. Now as I move into the US data the condition is measured in Wave a as hcond14 and this rate is now just above 5%, which is fine.
However, from wave b the incidence drops to just over 1% using hcond14n as hcond is not asked. I think from the documentation that hcond14n is newly diagnosed people. So to get the total incidence Can I add these individuals to those identified from wave a? Moreover, when I then consider wave c and onwards it seems that hcond14 and hcond14n are both asked and it seems that from here hcond14 is for people never asked before (which I suppose are new entrants to the survey) and hcond14n are previously interviewed people but newly diagnosed. In these cases can I add both of these 'increments' in incidence to those from wave a that already have indicated the presence of the condition to get the total incidence.
Thank you for any assistance.