Query slower when get data from page 1200

Select   Reg_ID,Reg_Service_ID,Reg_Patient_ID,Patient_Name,Doctor_ID,Doctor_Name,
		CASE WHEN EncounterSatuSehatID <>'-' and ConditionID <>'-'
		THEN 'Selesai'
		ELSE
		'Tidak Selesai'
		END AS 'Use Case 1' ,
		EncounterSatuSehatID,
		ConditionID,
		CASE WHEN CompositionID <>'-' and SatuSehatProcedureID <>'-' and ObservationID <>'-'
		THEN 'Selesai'
		ELSE
	    'Tidak Selesai'
		END AS 'Use Case 2',
		Status,
		Poly_Name,
		Reg_OpenDate
		from (
		Select A.Reg_ID,Reg_Service_ID,Patient_Name,Reg_Patient_ID,Doctor_ID,Doctor_Name,Reg_OpenDate,
			CASE WHEN B.EncounterSatuSehatID IS NULL
			THEN '-'
			ELSE 
			B.EncounterSatuSehatID
			END
			EncounterSatuSehatID,
			CASE WHEN C.ConditionID is null
			THEN '-'
			ELSE 
			C.ConditionID END ConditionID
			, CASE WHEN D.CompositionID is null
			THEN '-'
			ELSE 
			D.CompositionID 
			END  CompositionID ,CASE WHEN 
			E.SatuSehatProcedureID is null
			THEN '-'
			ELSE E.SatuSehatProcedureID END
			SatuSehatProcedureID ,
			CASE WHEN 	F.ID is null 
			THEN '-'  
			ELSE 
			F.ID
			END ObservationID,
		CASE WHEN Reg_Active = 1 and Reg_IsCancel =0
			THEN 'Aktif'
		 WHEN ((Reg_Active =1 and Reg_IsCancel =1) OR (Reg_Active=0 and Reg_IsCancel=1))
			THEN 'Batal' 
		ELSE
			 'Selesai'
		END 'Status',
		Poly_Name
		from Table1 A
		left join Table2 B on A.Reg_ID=B.Reg_ID
		left join Table3 C on A.Reg_ID=C.REG_ID
		left join Table4 D on A.Reg_ID=D.Reg_ID
		left join Table5 E on A.Reg_ID=E.RegID
		left join Table6 F on A.Reg_ID=F.RegID
		)A
		order by Reg_OpenDate desc
		 OFFSET (122614-1) *  5 ROWS 
		 		FETCH FIRST 5 ROWS ONLY