Database schema:

CREATE TABLE "Examination" (
	"ID" INTEGER -- example: ['14872', '48473'],
	"Examination Date" DATE -- example: ['1992-12-21', '1997-05-27'],
	"aCL IgG" REAL -- anti-Cardiolipin antibody (IgG), example: ['4.3', '1.3'],
	"aCL IgM" REAL -- anti-Cardiolipin antibody (IgM), example: ['4.6', '1.6'],
	"ANA" INTEGER -- anti-nucleus antibody, example: ['0', '256'],
	"ANA Pattern" TEXT -- pattern observed in the sheet of ANA examination, example: ['P,S', 'P'],
	"aCL IgA" INTEGER -- anti-Cardiolipin antibody (IgA) concentration, example: ['0', '3'],
	"Diagnosis" TEXT -- example: ['MCTD, AMI', 'SLE'],
	"KCT" TEXT -- measure of degree of coagulation, example: ['-', '+'],
	"RVVT" TEXT -- measure of degree of coagulation, example: ['-', '+'],
	"LAC" TEXT -- measure of degree of coagulation, example: ['-', '+'],
	"Symptoms" TEXT -- example: ['CNS lupus', 'AMI'],
	"Thrombosis" INTEGER -- example: ['0', '1'],
	CONSTRAINT fk_examination_patient FOREIGN KEY("ID") REFERENCES "Patient" ("ID")
)


CREATE TABLE "Laboratory" (
	"ID" INTEGER DEFAULT 0 NOT NULL -- example: ['27654', '30609'],
	"Date" DATE DEFAULT '0000-00-00' NOT NULL -- example: ['1991-09-17', '1991-09-11'],
	"GOT" INTEGER -- AST glutamic oxaloacetic transaminase, example: ['29', '34'],
	"GPT" INTEGER -- ALT glutamic pyruvic transaminase, example: ['31', '36'],
	"LDH" INTEGER -- lactate dehydrogenase, example: ['567', '579'],
	"ALP" INTEGER -- alkaliphophatase, example: ['154', '166'],
	"TP" REAL -- total protein, example: ['4.5', '5.1'],
	"ALB" REAL -- albumin, example: ['3.3', '3.4'],
	"UA" REAL -- uric acid, example: ['3.8', '4.2'],
	"UN" INTEGER -- urea nitrogen, example: ['36', '29'],
	"CRE" REAL -- creatinine, example: ['0.8', '0.9'],
	"T-BIL" REAL -- total bilirubin, example: ['0.3', '0.2'],
	"T-CHO" INTEGER -- total cholesterol, example: ['134', '165'],
	"TG" INTEGER -- triglyceride, example: ['205', '185'],
	"CPK" INTEGER -- creatinine phosphokinase, example: ['9', '10'],
	"GLU" INTEGER -- blood glucose, example: ['88', '134'],
	"WBC" REAL -- White blood cell, example: ['5.0', '10.4'],
	"RBC" REAL -- Red blood cell, example: ['2.6', '2.9'],
	"HGB" REAL -- Hemoglobin, example: ['6.4', '6.7'],
	"HCT" REAL -- Hematoclit, example: ['21.6', '20.3'],
	"PLT" INTEGER -- platelet, example: ['242', '227'],
	"PT" REAL -- prothrombin time, example: ['11.3', '12.0'],
	"APTT" INTEGER -- activated partial prothrombin time, example: ['84', '108'],
	"FG" REAL -- fibrinogen, example: ['27.0', '38.6'],
	"PIC" INTEGER -- example: ['320', '513'],
	"TAT" INTEGER -- example: ['108', '77'],
	"TAT2" INTEGER -- example: ['88', '113'],
	"U-PRO" TEXT -- proteinuria, example: ['0', '-'],
	"IGG" INTEGER -- Ig G, example: ['339', '771'],
	"IGA" INTEGER -- Ig A, example: ['145', '188'],
	"IGM" INTEGER -- Ig M, example: ['132', '46'],
	"CRP" TEXT -- C-reactive protein, example: ['0.6', '2.7'],
	"RA" TEXT -- Rhuematoid Factor, example: ['-', '+'],
	"RF" TEXT -- RAHA, example: ['<20.8', '<20.5'],
	"C3" INTEGER -- complement 3, example: ['30', '82'],
	"C4" INTEGER -- complement 4, example: ['26', '14'],
	"RNP" TEXT -- anti-ribonuclear protein, example: ['0', '1'],
	"SM" TEXT -- anti-SM, example: ['0', '1'],
	"SC170" TEXT -- anti-scl70, example: ['1', '16'],
	"SSA" TEXT -- anti-SSA, example: ['0', 'negative'],
	"SSB" TEXT -- anti-SSB, example: ['0', 'negative'],
	"CENTROMEA" TEXT -- anti-centromere, example: ['0', 'negative'],
	"DNA" TEXT -- anti-DNA, example: ['41.9', '18'],
	"DNA-II" INTEGER, 
	PRIMARY KEY ("ID", "Date"), 
	CONSTRAINT fk_laboratory_patient FOREIGN KEY("ID") REFERENCES "Patient" ("ID")
)


CREATE TABLE "Patient" (
	"ID" INTEGER DEFAULT 0 NOT NULL -- example: ['11408', '2110'],
	"SEX" TEXT -- example: ['M', 'F'],
	"Birthday" DATE -- example: ['1934-02-13', '1937-05-02'],
	"Description" DATE -- example: ['1994-02-14', '1996-12-01'],
	"First Date" DATE -- example: ['1993-02-10', '1973-01-01'],
	"Admission" TEXT -- example: ['+', '-'],
	"Diagnosis" TEXT -- example: ['RA susp.', 'PSS'],
	PRIMARY KEY ("ID")
)

Question: For patients with abnormal platelet level, state the number of patients with lower than normal range. How is it compare to the number of patients with higher than normal range?
Evidence: abnormal platelet level refers to PLT <= 100 or PLT >= 400; platelet level lower than normal range refers to PLT < 100; calculation = SUBTRACT(SUM(PLT < 100), SUM(PLT > 400)); platelet level higher than normal range refers to PLT > 400;

SQL:
SELECT SUM(CASE WHEN T2.PLT <= 100 THEN 1 ELSE 0 END) - SUM(CASE WHEN T2.PLT >= 400 THEN 1 ELSE 0 END) FROM Patient AS T1 INNER JOIN Laboratory AS T2 ON T1.ID = T2.ID