instruction: what is the maximum cost in a hospital involving a laboratory test for cpk-mb index since 5 years ago?
response: SELECT MAX(t1.c1) FROM (SELECT SUM(cost.cost) AS c1 FROM cost WHERE cost.patienthealthsystemstayid IN (SELECT patient.patienthealthsystemstayid FROM patient WHERE patient.patientunitstayid IN (SELECT lab.patientunitstayid FROM lab WHERE lab.labname = 'cpk-mb index')) AND DATETIME(cost.chargetime) >= DATETIME(CURRENT_TIME(), '-5 year') GROUP BY cost.patienthealthsystemstayid) AS t1