Can U Help Me Debug This!!!!

to all the experts can u help me about my codes Truncated incorrect DOUBLE value: 'NoOfPositives'
here's my code

select
ref_region.regionName,
ref_facility.facilityName,
ref_facility.adr,
ref_facility.facilityNo,

(select count(*)
from dto_initial_screening
where (dto_initial_screening.facilityNo = ref_facility.facilityNo and
dto_initial_screening.testDt between '2007-01-01' and '2008-01-01')) as 'TotalScreened',

(select count(*)
from dto_initial_screening
where (dto_initial_screening.testResult = 'POS' and
dto_initial_screening.facilityNo = ref_facility.facilityNo and
dto_initial_screening.testDt between '2007-01-01' and '2008-01-01')) as 'NoOfPositives'

from dto_initial_screening
left join ref_facility on dto_initial_screening.facilityNo = ref_facility.facilityNo
left join ref_region on ref_facility.adrRegionCd = ref_region.regionCd

where
('NoOfPositives') < (select Cast(paramVal as UNSIGNED) from ref_param where paramCd = 'minPositives')