instruction: list the top four most frequent lab tests that patients have been given during the same hospital encounter after receiving administration of electrolytes - potassium since 2 years ago.
response: SELECT t3.labname FROM (SELECT t2.labname, DENSE_RANK() OVER (ORDER BY COUNT(*) DESC) AS c1 FROM (SELECT patient.uniquepid, treatment.treatmenttime, patient.patienthealthsystemstayid FROM treatment JOIN patient ON treatment.patientunitstayid = patient.patientunitstayid WHERE treatment.treatmentname = 'administration of electrolytes - potassium' AND DATETIME(treatment.treatmenttime) >= DATETIME(CURRENT_TIME(), '-2 year')) AS t1 JOIN (SELECT patient.uniquepid, lab.labname, lab.labresulttime, patient.patienthealthsystemstayid FROM lab JOIN patient ON lab.patientunitstayid = patient.patientunitstayid WHERE DATETIME(lab.labresulttime) >= DATETIME(CURRENT_TIME(), '-2 year')) AS t2 ON t1.uniquepid = t2.uniquepid WHERE t1.treatmenttime < t2.labresulttime AND t1.patienthealthsystemstayid = t2.patienthealthsystemstayid GROUP BY t2.labname) AS t3 WHERE t3.c1 <= 4