Hello I am working with claims data from a health insurance. My dataset provides information about every claims from their insured patients, which means patients may appear more than once in the dataset if they have more than one claim. Patients are identified by their patient-ID   I would like to find out how many different patients I have in my dataset, meaning I would like to know how many different patient-IDs I have in my dataset.   If I try  proc freq data=dataset; tables patient_id; run; it just shows me how often a certain patient-ID appears in the dataset, but not how many different patient-IDs there are.   Any suggestions, how I could easily figure this out with a simple command?   Thank you! ... View more

Hi,   I am doing an interrupted time-series analysis and use the autoreg procedure. I have difficulties to understand what excatly the nlag= option does in this procedure as it changes my results minimally, but the follow-up graph practically not at all.   Would be great if someone could shortly explain the function of the nlag= option simple.   Thank you very much!   Here is my SAS coding: proc autoreg data=mydata; model measurements = preintervention intervention postintervention sin cos/ method=ml nlag=1 /*dw=5*/ dwprob covb; output out=autoreg_out predicted=pred pm=trend lcl=pred_l ucl=pred_u residual=resid predictedm=predm lclm=predm_l uclm=predm_u residualm=residm; run; ... View more

I am working on a study to evaluate the association of a policy change with the proportion of new drug users over time. I would like to create a graph based on my autoregression data (interrupted time-series analysis). Building the graph was successful, but I have problems with labelling the x axis.   The dataset is structured as follows (sample data): see attachment (excel) I applied following comands: data graph_proportion; set autoreg_out; if added=0 then do; if 1 <= period <= 48 then modeled1=pred; if 1 <= period <= 48 then band1_l=pred_l; if 1 <= period <= 48 then band1_u=pred_u; if 49 <= period <= 63 then modeled2=pred; if 49 <= period <= 63 then band2_l=pred_l; if 49 <= period <= 63 then band2_u=pred_u; end; if added=1 then do; projection=pred; end; label prop_newusers='Observed rate' modeled1='Modeled trend' projection="Predicted trend"; run; ods pdf style=HTMLBlue file="proportion" style=HTMLBlue image_dpi=600 path='Path xy'; ods graphics / reset width=450px height=350 px imagename="fig1a" imagefmt=PDF; proc sgplot data= graph_proportion noautolegend; band x=period upper=band1_u lower=band1_l / noextend; band x=period upper=band2_u lower=band2_l / noextend; scatter x=period y=proportion / markerattrs=(symbol=circlefilled color=CX203554 size=4) name="Observed rate"; series x=period y=modeled1 / lineattrs=(pattern=solid color=CX536582 thickness=2) name="Modeled trend"; series x=period y=modeled2 / lineattrs=(pattern=solid color=CX536582 thickness=2) name="none"; series x=period y=projection / lineattrs=(pattern=shortdash color=/*CX536582*/black thickness=2) name="Predicted trend"; refline 2006.5 / axis=x lineattrs=(pattern=dash thickness=2 color=grey); keylegend "Observed proportion" "Modeled trend" "Predicted trend" / location=inside position=topright across=1; yaxis label="Average proportion per 10000 patient" values=(0 to 20 by 1) labelattrs=(size=10) valueattrs=(size=8); xaxis fitpolicy=ROTATETHIN /*display=(noticks)*/ values=(1 to 63 by 1) valuesdisplay=('1Jan2015' '1Jan2016' '1Jan2017' '1Jan2018' '1Jan2019' '1Jan2020' '3Mar2020') labelattrs=(size=10) valueattrs=(size=8) display=(nolabel); run; I have 63 time-periods in total, each time-period represents a 30-day period between 1 January 2015 and 3 March 2020. So far I have only figured out how to label the x-axis at regular intervals. However, I want to label specific data points / time periods only, e.g. I need to specify to label period 1 as 1Jan2015, and period 63 as 3Mar2020, as well as some data points in between.   How can I label specific periods on the x-axis? What does the statement “fitpolicy” mean and do I need to change anything there? I tried changing the “by” command in  values=(1 to 63 by 1) but it cuts my graph at the end and the labelling is not precise because it distributes my labels at regular intervals.   Thank you for your help! ... View more