Re: SPSS Syntax MIXED Model

Posted by Zalihe on
URL: http://spssx-discussion.165.s1.nabble.com/SPSS-Syntax-MIXED-Model-tp5713934p5713971.html

Thank you for your reply Ryan,

I will explain you the research question in more detail for help. I have got a General Practice (GP) data set where each patient has repeated measurements on a blood test. Measurement dates are not same for each patient and the intervals between the measurements are not same either. The time_point indicates the order of the measurement like measurement 1, measurement 2, measurement 3...etc. There are up to 15 measurements per patient, the reason for variation between the number of measurements per subject is the missing data, so level 1 variable is the measurement taken within individual and level 2 variable is the patient. Repeated measured blood test is our dependent variable because the diagnosis of the particular disease is based on the value of this blood test. I am trying to investigate the effect of each independent variable such as age, gender, ethnicity... on dependent variable and also the effect on the decline of the dependent variable over time, so for example: is the person at age 30 has a higher decline from the measurement time point 1 to 2 compared to person at age 60 ? In that case, will a code like this be appropriate to use?


MIXED Blood_test_Value BY Gender Ethnicity Hypertension_diagnosis Diabetes_Diagnosis IHD_Diagnosis Anaemia_Diagnosis Obesity_Diagnosis Time_point WITH Age
  /CRITERIA = CIN(95) MXITER(150) MXSTEP(5) SCORING(1)
  SINGULAR(0.000000000001) HCONVERGE(0, ABSOLUTE) LCONVERGE(0, ABSOLUTE)
  PCONVERGE(0.000001, ABSOLUTE)
  /FIXED = Gender Ethnicity Age Hypertension_diagnosis Diabetes_Diagnosis IHD_Diagnosis Anaemia_Diagnosis Obesity_Diagnosis Time_point Gender*Time_point Ethnicity*Time_point Hypertension_diagnosis*Time_point
Diabetes_Diagnosis*Time_point IHD_Diagnosis*Time_point Anaemia_Diagnosis*Time_point Obesity_Diagnosis*Time_point Age*Time_point| SSTYPE(3)
  /METHOD = ML
  /PRINT = G R SOLUTION TESTCOV
  /RANDOM = INTERCEPT | SUBJECT(ID) COVTYPE(ID)
  /REPEATED = Time_point  | SUBJECT(ID) COVTYPE(AR1) .

Thank you for your help again.

Regards,

Zalihe.