Query taking too long to execute

I have a query that is taking very long to execute, literally takes more than an hour or two, which is not very productive.

I have a primary key on my main table and a foreign key on all LEFT OUTER JOIN tables.

Not quite sure how else to improve the execution time?

Any suggestions what I should be doing?

truncate table MyDay_Ward
insert into MyDay_Ward
	(location, unitno, [patient name], sex, age, location_description, [bed space], EpiStart, [episode los], [spell start]
	, TTO, AsAtDate, Clinic, AppointmentDate, theatre, OperationDate, [Into Ana], [Into Theatre], Duration, [Into Recovery]
	, APPOINTMENT, PROCEDURE1, APPOINTMENT_Lung, app_dttm, IDA, [Type], request_time, Status1, [Desc], request_time_ima
	, [Status], Desc1, [Exam name], CRIS_Date, Endoscopy, EndoscopyDate, PlannedDischarge, appointmentdate1, appointmentType
	, CommonName, [exam name1], event_dttm)
select 
	w.location	
	, w.unitno	
	, w.[patient name]
	, w.sex	
	, w.age	
	, w.location_description	
	, w.[bed space]
	, w.EpiStart	
	, w.[episode los]
	, w.[spell start]
	, w.TTO	
	, w.AsAtDate	
	, l.Clinic	
	, l.AppointmentDate	
	, t.theatre	
	, t.OperationDate	
	, t.[Into Ana]
	, t.[Into Theatre]
	, t.Duration	
	, t.[Into Recovery]
	, e.APPOINTMENT	
	, e.PROCEDURE1	
	, lu.APPOINTMENT_Lung	
	, m.app_dttm	
	, m.IDA	
	, c.[Type]
	, tp.request_time	
	, tp.[Status] Status1
	, tp.[Desc]
	, i.request_time_ima	
	, i.[Status]
	, i.[Desc] Desc1
	, cr.[Exam name]
	, cr.CRIS_Date	
	, en.Endoscopy	
	, en.EndoscopyDate	
	, pd.PlannedDischarge	
	, ci.appointmentdate appointmentdate1	
	, ci.appointmentType	
	, ci.CommonName	
	, cd.[exam name] [exam name1]
	, cd.event_dttm
from MyDay_Ward_Interim w
	left outer join MyDay_Lorenzo l on left(w.unitno,7) = left(l.patientid,7)
	left outer join MyDay_Theatres t on left(w.unitno,7) = left(t.unitno,7)
	left outer join MyDay_Echo e on left(w.unitno,7) = left(e.hospital_number,7) collate database_default
	left outer join MyDay_Lung lu on left(w.unitno,7) = left(lu.hospital_number,7) collate database_default
	left outer join MyDay_Mosaiq m on left(w.unitno,7) = left(m.ida,7) 
	left outer join MyDay_Chaplaincy c on left(w.unitno,7) = left(c.identifier,7) collate database_default
	left outer join MyDay_Therapies_PICS tp on left(w.unitno,7) = left(tp.reg,7) collate database_default
	left outer join MyDay_Imaging_PICS i on left(w.unitno,7) = left(i.reg,7) collate database_default
	left outer join MyDay_CRIS cr on left(w.unitno,7) = left(cr.[best hosp no],7) 
	left outer join MyDay_Endoscopy en on left(w.unitno,7) = left(en.unitno,7)
	left outer join MyDay_PICS_Discharge pd on left(w.unitno,7) = left(pd.unitno,7)
	left outer join MyDay_CIAO ci on left(w.unitno,7) = left(ci.unitno,7)
	left outer join MyDay_CRIS_Done cd on left(w.unitno,7) = left(cd.unitno,7)
group by 	w.location	
	, w.unitno	
	, w.[patient name]
	, w.sex	
	, w.age	
	, w.location_description	
	, w.[bed space]
	, w.EpiStart	
	, w.[episode los]
	, w.[spell start]
	, w.TTO	
	, w.AsAtDate	
	, l.Clinic	
	, l.AppointmentDate	
	, t.theatre	
	, t.OperationDate	
	, t.[Into Ana]
	, t.[Into Theatre]
	, t.Duration	
	, t.[Into Recovery]
	, e.APPOINTMENT	
	, e.PROCEDURE1	
	, lu.APPOINTMENT_Lung	
	, m.app_dttm	
	, m.IDA	
	, c.[Type]
	, tp.request_time	
	, tp.[Status] 
	, tp.[Desc]
	, i.request_time_ima	
	, i.[Status]
	, i.[Desc] 
	, cr.[Exam name]
	, cr.CRIS_Date	
	, en.Endoscopy	
	, en.EndoscopyDate	
	, pd.PlannedDischarge	
	, ci.appointmentdate 	
	, ci.appointmentType	
	, ci.CommonName	
	, cd.[exam name] 
	, cd.event_dttm