CREATE TABLE table_test_4 ("id" INT, "ejection_fraction_ef" INT, "systolic_blood_pressure_sbp" INT, "active_infection" BOOLEAN, "heart_disease" BOOLEAN, "renal_disease" BOOLEAN, "estimated_glomerular_filtration_rate_egfr" INT, "cardiogenic_shock" BOOLEAN, "diastolic_blood_pressure_dbp" INT, "symptomatic_hypotension" BOOLEAN, "severe_refractory_hypertension" BOOLEAN, "severe_left_ventricular_dysfunction" BOOLEAN, "NOUSE" FLOAT)

known estimated glomerular filtration rate ( egfr ) < 30 ml / min / 1.73 m^2 using the modification of diet in renal disease ( mdrd ) formula at visit 1 ( core study visit 10 )
SELECT * FROM table_test_4 WHERE estimated_glomerular_filtration_rate_egfr < 30
SELECT * FROM "table_test_4" WHERE "estimated_glomerular_filtration_rate_egfr" < 30