At which age did you start smoking:Time:Pt:^Patient:Qn:PhenX
at which age did you start smoking:time:pt:^patient:qn:phenx
At which age did you start smoking:Time:To identify measures at a point in time:^Patient:Quantitative:PhenX
at which age did you start smoking:time:to identify measures at a point in time:^patient:quantitative:phenx