Thti nghiem lam sang thuoc loai nghien ctiu can thiep.[r]
(1)TH l) NGHIEM LAM SANG NGAU NHIEN
I MUC TIEU
Mo td, thiet ke dung, va thuc hien dupc mot thii nghiem lam sang ngdu nhien
II NOI DUNG
Nghien ciiu thuc nghiem thuOng la mot phuong phap tot nhat nghien ciiu khoa hoc nham kiem dinh mot gid thuyet Trong vat ly hoc, nghien ciiu thuc nghiem thUcJng hay dupc sii dung Trong sinh hoc, nguOi ta cung thuong tien hanh nghien ciiu thuc nghiem tren dong vat Nghien ciiu thiic nghiem tren nguOi thuong it dupc sii dung
Muc dich cua cac nghien cUu benh chiing va thuan tap la nham xac dinh can nguyen cua benh Cac nghien ciiu can thiep thuc nghiem dupc trinh bay bdi thuong co' mot muc dich khac la nhdm xac dinh xem cac phuong phap dieu tri, phuong phap nao la tot nhat (xem hinh 1) Cac thong tin thu dupc til nghien ciiu thuc nghiem thuong rat co' ich viec xac dinh moi lien he can nguyen dupc hinh til cac nghien ciiu quan sat Vi du, cac chuong trinh chong hut thuoc la d phu nQ cd thai rat cd hieu qud viec phong tre em sinh thieu can Ket qud ndy se ho trp manh me cho mot ket luan rang hut thuoc la thOi ky mang thai la nguyen nhdn ddn den trd so sinh thieu can
*
Gi6ng nhu cac nghien ciiu thuan tap quan sat, cac thii nghiem lam sang la mot loai nghien ciiu tuong lai Cac doi tupng nghien ciiu dupc theo doi va gidm sat sii xuat hien benh qud trinh nghien ciiu Su khac can bdn giiia nghien ciiu thuan tap va thii nghiem lam sang la thii nghiem lam sang, ngudi nghien ciiu chu dong tac dong hay can thiep vao mot nho'm (nhdm can thiep) va nhdm khac khong nhan mot bien phap can thiep nao (nhdm chiing) Trong dd, nghien ciiu quan sat, nguoi nghien ciiu chi quan sat va khong he cd mot tac dong hay mot can thiep nao Phdn bo ngdu nhien benh nhdn vao cac nho'm dieu tri khac la dac trung cP bdn cua thii nghiem lam sang
(2)Thii nghiem lam sang ng iu nhien
Nghien ciiu thuan tap
Can thiep
I
Ket qua
Quan the nghien ciiu
Chon mau (ngiu nhien)
Nhiing ngudi tinh nguyen tham gia nghien ciiu
Ph&n bo ngdu nhien
Doi chiing
K e'jqui
Quan the nghien ciiu
Cho J m iu (ngiu nhien)
Nhiing ngUOi tinh nguyen tham gia nghien ciiu
Ket qud
Khong phoi nhilm
Ket qud
H inh 1 SU khac n h au giiia thii nghiem lam sang ngAu nhien va nghien ciiu th u an tap tu ong lai
1 Sir don g y tham gia n gh ien ciiu
Trong thii nghiem lam sang, chi co' mot nhdm nhan mot phuong phap dieu tri nao do', nhdm doi chiing thi khong nhan can thiep gi ci Do dd, cac doi tuong tham gia nghien ciiu phdi la nhiing ngudi tinh nguyen Nhung ngUOi duoc de nghi tham gia nghien ciiu thudng la nhiing nguOi co' nguy co cao xuat hien mot benh nao dd md ta can nghien ciiu (vi du nhu nhoi mdu co tim, mat khd nang sinh dd hoac di ta t bam sinh) Benh nhdn phdi dupc thong bao ve che nghien ciiu va dien vao m iu dong y tham gia nghien ciiu Neu benh nhdn khong dong y tham gia nghien ciiu, ho cd the thay doi loi song hieu biet ve yeu to nguy c0 va ddn den lam thap nguy co mdc benh Mac du vay, thii nghiem lam sang ngau nhien v in mang lai mot ket qud tot ma khong phuong phap nghien ciiu nao cd the dat dupc
2 P h an bo ngau nhien doi tUOng tham gia n gh ien ciiu.
(3)moi nhdm, sti khac biet ve ket qud cac nhdm se phuong phap dieu tri khac v6i mot dieu kien la cac yeu to khac deu giong va chi cd mot yeu to khac la phuong phap dieu tri Dieu chi cd the dat dupc cac ddi tupng nghien ctiu dupc chon ngdu nhien Chung ta can phdi phan biet dupc sU khac gitia ltfa chon ngdu nhien cac doi tupng tham gia vao nghien ctiu (cd the giong gitia nghien ctiu quan sat va nghien ctiu thuc nghiem) va phdn bo ngdu nhien cac doi tuong nghien ctiu da dupc chon vao nhdm can thiep va nhdm doi chting (chi xdy d nghien ctiu thuc nghiem)
3 Loai trvf cac sai
Cd doi tupng nghien ctiu va ngudi nghien ctiu deu cd the dnh hudng den ket qud cua thti nghiem De gidm cac sai so loai nay, nguOi ta thudng sti dung ky thuat "lam mil" Trong ky thu at "lam mil kep", cd ngudi nghien ctiu va doi tupng nghien ctiu deu khong biet benh nhdn dupc phdn bo vao nhdm nao Ky thuat ndy dac biet phdi dupc tien hanh nhting nghien ctiu md ket qud thuOng mang tinh chu quan nhu "kha hon", "khong thay ddi" hay "xau di" Ndu ket qud nghien ctiu cd tinh khach quan, nhu chet, dot quy, khong can thiet phdi dp dung ky thuat "lam mil"
4 Anh h u d n g g ia ta o c u a c h a t tr o (Placebo effect)
NguOi ta da biet ro mot hien tupng y hoc la benh nhdn dupc dieu tri mot loai chat tro (vi du nhu vien duOng) ho thuOng cdm thay cd nhting tien trien tot hon v'e m at lam sang so vdi benh nhdn khong dupc dieu tri bdng chat tro ay Hien tupng thuong dupc gpi la "dnh hudng gid tao cua chat tro" va phdi dupc xem xet thiet ke cac thti nghiem lam sang neu ta muon quy ket hieu qud nghien ctiu can thiep la chinh phuong phap dieu tri can thiep chti khong phdi la dnh hudng cua sU dieu tri Do do, ngudi ta thudng sti dung mot chat tro de dieu tri benh nhdn md benh nhdn d nhdm chting khdng the nhan biet dupc, cd nghia la chat tro giong hoan toan vdi thuoc d nhdm dupc dieu trj can thiep v'e hinh dang, mdu sac Chi cd nhu vay, su khac ve ket qud dieu trj gitia cac nhdm se la sU khac v'e phuong phap dieu trj
5 P h an tich ket qua.
Khi phdn tich ket qud cua thti nghiem lam sang, ngudi ta thudng dua nhieu du doan Dau tien ngudi ta tien hanh so sanh gitia cac nhdm can thiep va nhdm chting xem su giong v'e cac yeu to nhu tuoi, giong, chting toe va dac biet la cac yeu to nguy co da biet co nam nghien ctiu hay khong (ket qud cua sti phdn bo ngau nhien) Sau dd, ngudi ta tien hanh phan tich dnh hudng cua phuong phap can thiep (vi du, chuong trinh chong hut thuoc la se lam gidm ty le ngUOi hut thuoc la d nhdm can thiep) Cuoi citng, budc phan tich chu yeu cua thu nghiem lam sang la kiem djnh xem lieu gia thuyet dua rdng yeu td nguy co dnh hudng den stic khoe cd dung khong (vi du, hut thuoc la lam tang nguy cO ung thu dudng ho hap dudi)
(4)ra, budc phan tich kiem dinh gid thuyet phdi dua tren nguyen tac la moi doi tupng nghien criu mot da dupc phdn bo ngdu nhien vao cac nho'm ho phdi dupc dua vao phdn tich No'i mot cach khac la neu ta loai bo mpt cach co' chon loc benh nhdn phdn tich ket qud se lam mat di y nghia cua viec phdn bo ngdu nhien benh nhdn vao cac nhdm nghien ctiu
III BAI TAP
Nguoi ta da tien hanh mot thti nghiem lam sang ngdu nhien de danh gid cac phuong phap dieu tri benh ddi duOng
Thti nghiem ndy bao gom cac buOc nhu: xay dung quy trinh thu thap cac so lieu co' the so sanh dupc vdi nhau, phdn bo ngdu nhien benh nhdn vao cac nhdm dieu tri bdng cac phuong phap khac bao gom cd nho'm so sanh dupc dieu tri bdng chat tro, danh gid bdng phuong phap "lam mil kep" cac loai thuoc uong, theo doi benh nhdn mot thdi gian ddi, thu thap, bien soan va gidm sat cac so lieu nghien ctiu
Ngudi ta lua chon nhting benh nhdn dai dudng khdng phu thuoc insulin va khdng ddi hoi phdi dieu tri insulin Loai ddi dudng chiem chu yeu (tren 90% tong so benh nhdn ddi dudng)
Thti nghiem ndy co' hai muc tieu chinh:
1 Danh gid hieu qud cua cac phuong phap dieu tri 1dm dudng huyet viec du phong cac bien chting vie mach mdu
2 Nghien ctiu hch sti tu nhien cua benh ve mach mdu
NgUdi ta da dp dung nhting che dieu tri sau nghien ctiu nay:
1 Dieu tri bang insulin vdi nhting lieu lupng khac de tri mtic dudng huyet d mtic binh thudng
2 Dieu tri bang insulin vdi lieu lupng chuan: Insulin cham U-80, 10-16 don vi moi tiem theo dien tich co the
3 Dieu tri bdng Tolbutamide l,5g/ngay theo dudng uong
4 Dieu tri bang lactose tro (placebo) dudi hinh dang va lieu lupng giong nhu cac thuoc dieu tri dudng huyet
Tat cd cac nho'm tren deu cd mot che an kieng nhu Ket qua:
Cac nha nghien ctiu dd thu dupc nhting ket qud bat ngd sau:
1 Insulin khdng cd hieu qud hon so vdi chi dp dung che an kieng sudt ddi d nhting benh nhan dai dudng
2 An kieng cong vdi dieu tri bang tolbutamide khdng co' hieu qud hPn so vdi chi dp dung che an kieng sudt ddi d nhting benh nhdn dai dudng
3 Cd sU tang cd y nghia thong ke ty le chet benh mach mau d nhdm dupc dieu tri bdng tolbutamide so vdi nho'm dupc dieu tri bdng placebo
C&u hoi:
(5)2 Khi nao ky th u at "lam mu kep" la can thiet nhat va it can thiet nhat? No cd nghia la nhu the nao?
3 Hien rat kho' tien hanh dupc mot thii nghiem lam sang nhu the Tai sao? Neu khong cd nho'm dieu tri bang placebo, ta se khong thu dupc nhting ket luan gi? Tai phan bo n giu nhien benh nhan vao cac nhdm dieu tri la can thiet va no' dat dupc muc dich gi?
T r a ldi:
1 Nhung ket qud dat dupc tti nghien ctiu nay, cung nhu nhting nghien ctiu khac, chi ap dung dupc cho nhting quan the tuong tu nhu quan the nghien ctiu Tuy nhien, thti nghiem nay, khong co' vain de gi bdi vi nhting benh nhan nghien ctiu dai dien cho phan Ion nhting benh nhan dai duOng phong phu thuoc insulin
2 Ky thuat "lam mil kep" la can thiet de loai trti cac sai chech chu quan gay c l ngudi nghien ctiu va doi tupng nghien ctiu Ky thuat la can thiet nhat cac nghien ctiu ma ket qua mang tinh chu quan nhu "khd hon", "khong thay ddi" hay "xau hon" Nd it can thiet nhat cho cac nghien ctiu voi nhting ket qud khach quan Ky thuat se khong cho ca nguOi nghien ctiu va doi tupng nghien ctiu biet ve che dieu tri tren placebo
3 Tat cd nhting benh nhan tham gia nghien ctiu da dong y tham gia nghien ctiu sau da dupc thong bao ve nghien ctiu Ho da dupc theo doi chat che moi dnh hudng hay trieu chting Mot chuyen gia gidi ve benh dai duPng da tham gia vao thiet ke thti nghiem va cho rin g nhdm placebo se co' ket qud tuong tu nhu cac nho'm dieu tri bang thuoc duPng huyet Va cuoi cung, dieu da dupc chting minh la dung
4 NguPi ta cd the thu duoc nhting ket luan quan nhat neu khdng tien hanh dieu tri placebo Do' la:
a Insulin khong tot hon so vOi placebo
b Tolbutamide cd lien quan vdi tang nguy co tti vong va benh mach mau (cd y nghia thong ke) so sanh voi placebo
5 Phan bo benh nhan ngau nhien vao cac nho'm dieu tri la can thiet vi chi dd su khac biet ve ket qud dieu tri mdi co' the qui cho la tien hanh cac thti nghiem dieu tri khac Neu khong tien hanh phdn bo ngdu nhien, sU khac ve ket qud dieu tri co' the’ la cac dac trUng khac cua cac nho'm nghien ctiu Phdn bo ng iu nhien se mang lai mot su phdn bo nhu cac yeu to nguy co (vi du tuoi, gidi, mtic nang cua benh) d cac nho'm Day la mot khai niem co bdn cua thti nghiem lam sang n g iu nhien
IV CACH TIEN HANH NGHIEN CUU
M O T T H U NGHIEM LAM SANG NGAU NHIEN
A N H A C LAI MOT VAI KHAI NIEM CAN THIET
(6)phap dieu tri chinh ngudi thay thuoc dieu tri chu dong "ap dat" vao, can thiep vao qua trinh d iin bien cua benh (lam cho benh mau khoi, hoac benh se khoi triet de, hoac it di chting de lai )
2 thti nghiem lam sang la mot nghien ctiu tUdng lai, dd chinh ngudi thay thuoc dieu tri phdi theo doi, gidm sat xac nhan sti xuat hien cua hieu qud dieu tri mong ddi tuong lai
3 Vi thti nghiem lam sang la mot nhting nghien ctiu phan tich dich ti, nen bao gid cung phdi thiet lap mot nhdm doi chting, vdi ty le ve so lUdng hoac 1/1, hoac 2/1 thuoc nho'm doi chting dupc chon nhu the nao, nghia la ddm bdo sU tuong dong den dau so vdi nho'm chti ctiu
4 Vi cung la mot nghien ctiu ngdu nhien, nen yeu to ngdu nhien cung van la yeu to chi phoi lam gidm cac sai so giong nhu d cac nghien ctiu ngdu nhien khac Song d day qud trinh chon cac doi tUdng bang ngdu nhien, lai bieu thi dudi dang phdn bo viec cd nhan va khong nhan bien phap can thiep cho ho, de cuoi cung ta co' dupc nhting se vao nho'm chu ctiu (cd nhan yeu to can thidp) va nhting se vao nhdm doi chting (khong nhan yeu to can thiep can nghien ctiu, m a nhan yeu to can thiep cu hoac placebo de doi chting)
5 Ky th u at "lam mil" phdi dupc van dung triet de Nen tien hanh ky th uat "lam mil kep" Cd the dUdc thi nen tien hanh "lam mil ba" (cd benh nhdn, cd thay thuoc lam dieu tri va cd ngudi xti ly ket qud deu khong biet) do' quan hdn cd la nhting ngudi benh dupc can thiep dtit khoat khong dupc biet minh dang "bi lam nghien ctiu", trti nhting nghien ctiu phdi sti dung ngudi tinh nguyen Ngay cd trudng hdp ndy thi ho lai cang khong the dupc biet minh dupc hay bi cl nhdm nghien ctiu nao, no' dnh hudng rat ldn den hieu luc nghien ctiu (gay nhting sai chech khong ludng dupc) va lai la van de dao dtic y hoc ntia
Ky th u at
lam mil
NgUdi bi lam mU tro n g qua trin h nghien cUu
benh nhan ngUdi nghien ctiu ngUcli xii ly s6 lieu
mil ddn CO khfing khftng
m u kep CO CO khAng
mil ba CO CO CO
B MOT BAI TAP VE MAU NGHIEN ClJU THO NGHIEM LAM SANG
Mot thay thuoc muon thti xem tac dung nhanh cua mot loai thuoc sot ret mdi so vdi loai thuoc cu hien dang dung
Tieu chuan dat la het ky sinh triing v6 tinh vong 36 gid sau dung thuoc 1 TrUdc h et ta hdy tin h cd mau
De tinh dupc cd mdu toi tieu vtia du, can phdi:
(7)ta se dung de kiem dinh sU khac biet ty le khoi cua loai thuoc tren nhdm ngudi dung loai thuoc dd Thudng dung mdc y nghia 0,1 hoac 0,05 hoac 0,01
bj An dinh mot luc mdu nhat dinh Luc mau la mong muon cua chung ta de phat hien dUdc su khac biet (cd y nghia thong ke) cua loai thuoc nay, ndi khac di luc mau la xac suat co' dUdc ket qud nghien criu co' y nghia Luc mau phu thuoc vao:
+ Su khac biet cua cac ty le khoi benh thuc su la bao nhieu Su khac biet cang ldn, thi luc mdu cang ldn
+ Cd mdu la bao nhieu Cd mdu cang ldn, thi luc mdu cang ldn Nhting luc mdu thudng dung la 80%, 90% va 95^
c) An dinh mot su khac biet cd gia tri ve lam sang gitia cac ty le cua nhdm ngudi sti dung loai thuoc dd Su khac biet la bao nhieu de co' dude gia tri ve lam sang thi phdi cac thay thuoc lam sang tu an dinh dua tren y nghia thuc te lam sang Thi du su khac biet la 5% se rat cd gia tri neu ty le khoi dang tti 5% len 10%, nhung se it cd gid tri hon nhieu neu ty le khdi dang tti 90% len 95% Tuy nhien, day chi la thi du ve cac so, cac thay thuoc lam sang can can cti vao nhieu khia canh khac, ve y nghia xa hoi cua van de, y nghia y hoc va y te cua van de, tinh bien va nghiem cua benh nghien ctiu
De cd dUdc su khac biet ndy, tat nhien chung ta da cd ty le khdi ddi vdi loai thuoc dieu tri dang dung, cong viec lai la Udc ludng ty le khoi ddi vdi loai thuoc mdi ntia md thdi.
d) Cong thitc tin h co mdu. Cd nhieu
Ddn gian nhat la:
Z i -ti/2 p q F n =
-D“
trong do': p la tru ng binh cua ty le d nhdm: Pi + P2
P= -2 q la sd bu cua p den 1:
q = 1-p
F la binh phUdng cua tong (Z a/2 va Zft) F = (Za/2 + Zj i r vdi :
Z„/2 Id gia tri tdi han cua phdn bo chuan ting vdi mtic y nghia phia cua sai lam a da an dinh
a = ,0 thi Za/2 = ,9 a = 0,01
a = 0,1
Z/i la gia tri tdi han phia tUdng ting vdi luc mdu 1- (i da an djnh (j = 80% thi Zp = 0,86
90% =1,28
(8)De giup ngudi nghien ciiu, ngudi ta da tinh s in cac gia tri cua F d cac miic y nghia va liic mdu thudng dimg:
_
M ac Luc mSu
y nghia
50% 80% 90% 95%
0.1 2,7 ,2 ,6 10 ,8
0.05 3.8 7,9 10,5 13,0
0,01 ,6 11,7 14,9 17,8
Con D la khac biet ty le d nhdm (nd chinh la hieu so gitia ty le nay, chung duoc bieu thi bang cung don vi)
Thi du neu chung ta an djnh:
Miic y nghia a = 0,05 -* Z«/2 = (thay cho 1,96)
Liic mdu - fi = 0,90 thi F se la 10,5 (hang 0,05 cot 90% bdng F tren day) Neu D = 0,10 (Ty le khoi cua thuoc cu pi = 70%, cua ty le thuoc mdi p2 = 80%, thi
0,7+0,8
P = 2
thi se cd:
-0 ,7 )
n =
2 x 0,75 x 0,25 x 10,5
(0,1)2
= 394 7r 400
nhu vay can phai lay moi nho'm 400 benh nhan vao mdu nghien ciiu: 400 ngudi dieu tri thuoc cu va 400 ngudi dieu tri thuoc mdi
2 Chi dinh so benh nhan vao nhom.
S a u k h i loai tril n h u n g b e n h n h a n cd n h iin g b e n h k e t hdp hoac m a n tfn h xet co th e a n h hUdng d en q u a tr i n h d ie u tr i , 800 b e n h n h a n d u tie u c h u a n dUdc lay vao n g h ie n ciiu L ap d a n h m uc c u a 800 b e n h n h a n n a y , te n xep th e o v a n chii cai roi chon n g a u n h ie n ho vao n h o m , b a n g cac ky t h u a t p h a n bo k h o i n g a u n h ien Viec p h a n bo k hoi n g a u n h ie n n a y co ta m q u a n tro n g q u y e t d in h d e n k e t qua n g h ie n ciiu
3 Thiic hien n gh ien ciiu
(9)gidm sat rat chat che) nhung cung phdi lai la btfdc quyet dinh den tinh chinh xac cua ket qud nghien ciiu
4 Tinh ket qu a n gh ien ctiu.
Gid sti ta thu dupc ket qud sau, bdng 2x2:
36 girt sau
T h u6c du n g d ieu trj
het KST KST C'Ong
T h u o c mrti 350 50 400
T h u o c cu IKO 120 400
1 Triidc het ta tim "y nghia thong ke" cua ket qud nghien ciiu Day la mot nghien ciiu ty le nen ta se dung mot trdc nghiem y nghia ve sir khac biet giCfa ty le:
X iii u = 35,5
Ket qud nghien ciiu cd y nghia thong ke P ngUPng p<0,05 nhu da du kien, ta loai bo H„ (2 ty le la khong khac biet) va chap nhan H I sau: Ty le het KST vo tinh cl nhdm duoc dieu tri bdng thuoc mdi cd khac biet ty le dd d nhdm dieu tri bang thuoc cu Su khac biet cd y nghia thong ke d nguang p < 0,05
2 Ta tinh ty le d nhdm:
- Nhom dung thuoc mdi: 350/400 = 0,87 ± 0,0057 - Nhdm dung thuoc cu: 280/400 = 0,70 ± 0.0105 Tinh RR: 0,87/0,70 = 1,25
E KET LUAN
Trong nghien ciiu, viec chi dinh vao nhdm chu ciiu va ddi chiing dupc thuc hien ngdu nhien sd benh nhan dupc tinh theo cO mdu phu hpp vdi cac dieu kien an dinh Khi tien hanh nghien ciiu, ky th u at "lam mil kep" dupc gidm sat triet de, nen cd the’ cho rdng ket qud nghien ciiu khong chiia sai sd quan Bay gid, van dung tieu chuan ve tinh nguyen nhdn, ngtfOi ta thay chung deu dupc thoa man nghien ciiu, nen cd the ket luan rang thuoc mdi cd ty le sach KST sot ret vong 36 gid cao hon so vdi ty le neu dung thuoc cu: 0.87 so vdi 0,70
Sau day, la trich bdng de tien viec so sanh (bdng Fisher va Yates’) d mot bac tu do: Xac suat P Gia trj X~
0,001 10,827
0,01 6,635
0,02 5,412
0,05 3,841
0,10 2,706
(10)DIEU TRA NGHIEN CUU SUC KHOE CONG DONG NGHIEN CUU NGANG
I MUC TIEU
- Xac nhan vai tro quan cua nghien ciiu ngang dich t i hoc - Nhan biet nhiing lpi diem cua mau chum ngiu nhien
- Phan biet dupc cac dac tinh cua thiet ke lay m iu chum
II NOI DUNG
TrUPc het cln phan biet cac nghien ciiu quan sat vPi cac nghien ciiu can thiep: d nghien ciiu quan sat thi ta can phai chon cac cd the vao nghien cUu, nghien ciiu can thiep thi ta lai chi dinh loai can thiep cho cac ca the (nhu phiiong phap dieu tri cho cac benh nhan ch in g han) Doi khi, cd nhiing nghien ciiu ket hop ca 2: thi du nghien ciiu dieu tri sot ret quan the, thi can thiep dieu tri (dung thuoc hoac placebo) duoc chi dinh cho moi tre uong hang tuan, va mpt mau 20% so tre dd dupc chon ra de giam sat bang quan sat hang thang.
Nghien ciiu ngang thuoc loai nghien ciiu quan sat Can chu y den mpt so diem quan nhu sau:
1 Nghien ciiu ngang gan lien vPi ty le hien mac, nghia la nghien ciiu ngang chi dupc sii dung de mo ta? (cd rat it ket qua nghien ciiu ngang dupc dua sang dich t i hoc phan tich, nhiing dac trUng nguy co nghien ciiu la bam sinh, khong thay doi sudt mot ddi nguoi, thi du mau mat, nhdm mau)
2 Nghien ciiu ngang cung g in lien voi khoang thoi gian diin bien cua hien tupng siic khoe ma ta nghien ciiu quan the: chi nhin nhan hien tupng siic khoe dd (thi du tinh hinh benh tat) mpt thoi diem nhat dinh: nen nguoi ta hinh dung ket qua ngang la mot biic anh chup nhanh v'e tinh hinh cua hien tupng siic khoe ma ta nghien ciiu Tuy nhien, cum til "thoi diem" d day dupc nhin nhan mot cach tuong doi, tuong ling vdi mot "thdi gian ngln" Phan Ion cac nghien ciiu v'e tinh hinh cac benh truyen nhiem cap tinh theo kinh nghiem, nguoi ta thuong an dinh thoi gian n g ln la tuan
(11)dung de danh gid: danh gia mot hien tuong siic khoe, danh gia tien hoac ket qua cua mot chuong trinh y te
4 Voi y nghia mo td, dich t i hoc hien dai, viec mo td mot hien tuong siic khoe nao dd bao gid cung kem theo viec mo td yeu to nguy co cua nd (neu khong mo td yeu to nguy co kem theo se coi la thieu sot viec mo td, va nghien ciiu khong phuc vii loi ich thuc te)
Voi y nghia danh gid, viec mo td yeu to nguy co cung rat can thiet, no' gidi dap nguyen nhdn cua tinh trang duoc danh gid, va chi cho cach khdc phuc tot hon niia tinh trang do'
5 Nghien ciiu ngang co' the duoc sii dung de mo td, danh gia cd cac bien dinh luong ldn dinh tin h, cac bien lien tuc va bien roi rac Nhung deu tuan thu nhiing budc di nhu va vOi nhiing nguyen ly nhu
6 Nghien ciiu ngang mo td mot tinh hinh y te, mot hien trang siic khoe VOi muc tieu la hinh duoc mot gid thuyet mang tinh nguyen nhan ve van de nghien ciiu (khac han vdi nghien ciiu tuong lai: nghien ciiu tuong lai nhdm kiem dinh mot gid thuyet nhan qud, va bao giO cung phdi sii dung nhdm doi chiing nghien ciiu cua minh)
7 Nghien ciiu ngang mo td hien trang nen ket qud duoc dung viec quan ly, dieu hanh, danli gid tinh hinh thuc thi mot chuong trinh, mot chu truong y te, tinh hinh lUu hanh cua mot benh, dien bien cua mot hien tupng siic khoe (con muon dieu tra, nghien ciiu ve nguy co hoac nguyen nhdn cua mot benh chdng han, phdi sii dung cac thiet ke nghien ciiu dich t l hoc phan tich)
8 Nghien ciiu ngang cd the sii dung vdi mdu ngdu nhien don, mdu tang hoac mdu chum hoac cac mau do' ket hop NhUng ngudi ta thudng sii dung mdu chum de nghien ciiu ngang tren nhung quan the ldn
9 Nghien ciiu ngang tien hanh quan the, thuc chat la nhung cuoc dieu tra cong dong, duoc mo td chi tiet cuon thuc hanh ndy Day la mot phat trien quan cua dich t i hoc
10 Thong thudng thi cac nghien ciiu ngang deu tien hanh tren mot mdu nhat quan the (de tim mot ty le hoac mot so trung binh cua quan the dd) Con trudng hop dac biet nhu muon udc luong sii khac biet cac ty le (hoac so trung binh) d quan the khac chdng han thi cong thiic de tinh cd mdu co' khdc vdi cd mdu tinh cho trudng hop lam mot mdu nhat quan the
11 La mot nghien ciiu theo mdu, ket qud nghien ciiu ngang se khong "chap" duoc vdi ket qua nghien ciiu quan the toan bo, vi bao gid cung cd sai so nghien ciiu mau, sai so gpi la sai so mdu, no' bao gom loai chinh:
Sai so he thong vd sai so ngdu nhien.
Chung ta co' the lam gidm den tdi thieu sai so he thong bdng cach thiet ke that can than chi tiet cac thu tuc lay mdu va tuan thu triet de nhung thu tuc dd thiic thi Vd cung cd the lam gidm sai so ngdu nhien den miic chap nhan dupc bang cach chon mot co mau hpp ly
(12)do mot vai ca the khong du tieu chuan nghien ctiu lai dupc chon vao mdu, sai so ngudi tra loi ) Cung co' nhting sai so khong thuoc viec lay m iu khong de cap d day nhung cung can rat chu y toan bo qua trinh nghien ctiu
12 Mot vai dinh nghia
- Don vi lay m iu: cd the la mot nguoi, mot ho gia dinh, mot truOng hoc
- Quan the dinh danh (hay quan the tham kh&o): la quan the ta quan tam den tieu thtic can nghien ctiu
- Q uin the nghien ctiu (hay quan the dieu tra): la tap hop cua cac don vi lay m iu tti dd ta lay m iu Tren thuc te, thi quan the nghien ctiu hep hon nhieu so vdi quan the dinh danh
- Thiet ke m iu: sP dd de chon cac don vi lay mau vao mau tti q u in the nghien ctiu - Khung m iu: danh muc cac don vi de chon m iu
13 M iu ng iu nhien don co' the dupe dung nhung it dung dieu tra cong dong M iu ng iu nhien don la hinh anh co ban nhat cua cac m iu ngau nhien
- Phdi lap mot khung m iu la mot ban danh muc quan the nghien ctiu cd ten va ma sd (sd thti tU) tti den N
v „ _
- Tti do' rut ngau nhien so don vi can thiet cua cd m iu bang nhieu ky thuat ngau nhien, dd bang sd ngiu nhien thuong dupc dung bien
TrUdc tien hanh mot ky thuat ngau nhien nao dd, bao gid cung can phai quy udc trudc mot sd diem nhu hudng ngiu nhien, phia ng iu nhien va can phai chu y den sd chti sd, sd ky tu cua sd ngiu nhien
M iu ngiu nhien don dupc thuc hien b ln g cach lay m iu he thong 14 Mau bac: la loai mau dupc dung bien nhat de dieu tra cong dong
Tren thuc te, nhieu tinh hudng khdng the thuc hien dupc mau ngau nhien don hoac m iu he thong nhu trudng hpp quan the qua ldn (quan the vd han), khdng cd khung m iu (hoac khung m iu khdng tin cay dupc) hoac q u in the qua phan tan tren nhting lanh tho rong ldn
Mot nhting mau bac la mau chum, lay nhu sau:
1 Quan the thudng tap hpp tu nhien cac chum, nhu lang, quan huyen, mot cao oc Ta se lap danh muc cua cac don vi bac dd
2 Chon n giu nhien cac don vi bac dd
3 Trong moi don vj bac vtia dupc chon, ta lap danh muc cac dpn vi bac (ho gia dinh hoac ca the) roi ta chon cac dpn vi bac vao m iu cho du co m iu
Mau bac co' nhieu lpi diem:
- Chi phi: khdng phai qua qua nhieu chum
- De lam: chi can lap danh muc cac chum da dupc chon, va cd the lam chung ta den chum dd
(13)cd m iu ldn hdn Thi du: dieu tra so hien tuong duong tinh huyet vdi HIV d Kinshara, Zaire, cd m iu ldn (vi ty le duong tinh thap) lai phai trai rong khdp pho, nen khdng lam m iu ngiu nhien don dupc NgUdi ta da chia 266 khu vUc, chon 100 khu vUc, va moi khu vUc chon ngau nhien 100 ngudi ldn de phong van va lay mau xet nghiem
15 M iu tang n giu nhien cung thudng dupc dung dieu tra cong dong
Trong cac cuoc dieu tra nghien cUu, ddi ta muon c d nhung ket qua rieng cua tung
khu v U c khac nhau, va muon chic chin la moi khu vUc c d rieng c d m iu tuong xUng cua
n d Trudng hop nay, nguoi ta coi moi khu vUc la tang, va d moi tang se chon mot
m iu ngau nhien rieng biet ihoac ngau nhien don hoac bac)
Tang khdng nhat thiet phai la cac khu vUc theo dia du, ma c d the la nong thon-thanh
thi, nam-nti, tre-gia m iln la ta thay neu lam toan bo thi Udc lupng se khdng chinh xac,
vi cac U dc lupng d cac tang la khac
Thi du ngudi ta da tien hanh mot cuoc dieu tra v'e ty le chet tre d Gambia, ma nhUng cuoc dieu tra co ban trudc dd cho thay rin g cong tac cham soc sUc khoe ban dau d cac lang la rat khac nhau, nen ngudi ta da dieu tra ty le chet tre rieng d tang cd va d tang chua cd cham soc sUc khoe ban dau
III CACH TIEN HANH M O T NGHIEN CUU NGANG OE DIEU TRA NGHIEN CUU SUC KHOE CONG DONG
1 Chon van die n gh ien ciiu
La nhung van de U u tien bo phan cong tac cua minh, dupc tinh toan phu hpp
vdi cac nguon luc cd the cd, dam bao nghien cUu cd ket qua, va ket qua la cd hieu qua (Nghien cUu ngang thuoc loai nghien cUu Ung dung thuc te) Hieu qua cua mot chuong trinh, mdt dich vu, mot tinh huong, mdt hoat dong y te dupc hieu theo nghia la cai thien dupc mot hien tran g y te, hoac lam giam thieu mot hien tupng sUc khoe nang n'e Nhu vay phai can cti vao muc tieu cua nhUng van de Uu tien ma dat van de nghien cUu
O day, chiing ta cung can phan biet nhting khai niem v'e hieu luc lam sang, hieu luc dich t§, hieu luc y te de dat van de nghien cUu ro rang
2 Xac dinh tieu th iic nghien ciiu: Quan th e va mau n ghien ciiu
Dudi day, se de cap den cac nghien cUu ngang n him tim kiem ket qua dudi dang mot ty le cho d i hieu Khdng n h ic lai dinh nghia v'e mot ty le, d day chi ndi v'e khia canh bdn than nd la mot ty sd dudi dang mot phan so ma td sd la sd dem cua dac trUng nghien cUu va mau sd la so dem cua don vi nghien cUu (trong quan the tren dd dac trUng nghien ctiu dupc khao sat)
a) Dac trung hay tieu thitc nghien ciiu.
(14)Thi du: bang tieu chuan chan doan hoi chiing soc nhiem doc d phu nti dung kho hanh kinh sieu tham Reily cd trieu chdng sot, ngudi ta da dinh nghia sot d day la ngudi cd than nhiet tii 38°9C trd len, hay chudng trinh TCMR duoc coi la cd tiem BCG co ket qud cd seo BCG
b) Quan the.
Cd nhieu khai niem ve quan the tren dd xay dien bien tieu thuc nghien ctiu Sir dung loai quan the nao phu thuoc vao muc tieu nghien ctiu Quan the cung phai duac dinh nghia ro rang Thi du: tre 12 - 23 thang bao gom nhung tre bat dau ky niem dUdc sinh nhat lan thti hai khong phan biet gai hay trai, kinh te, van hoa, xa hoi
c) Mdu vd quan the.
Thudng quan the la rat ldn khd cd the thu thap thong tin tti ta t ca cac ca the quan the dd Nen chiing ta thudng chon mot mau va thu thap thong tin tu car ca the mau nay, vdi mong muon la mau la dai dien cho quan the
Nhung cd cd the dieu tra quan the toan bo, thi nghien ctiu mau van tot hon vi nghien ctiu mdu:
- Tiet kiem thdi gian nhan life vd chi phi
- Chat ludng thong tin tap trung dUdc thdi gian va cac nguon luc khac- cho cac dti kien tin cay tren moi ca the
- Mau chum it chinh xac han mdu ngdu nhien dan nhung van dap Ung duoc cac ldi die in nay, so don vi thong ke quan the dieu tra la rat ldn
3 Thiet ke mau nghien ciiu
at Cd mdu: Trong viec tinh cd mdu (theo cong thtic hoac theo bdng tinh sdn d sach dich te nao cung cdt bao gid chung ta cung can phdi cd mot so y niem cu the ve van de nghien ctiu, bao gom bat buoc quyet dinh sau:
- Udc luong ty le dac trung nghien ctiu neu nhdm nghien ctiu mot ty le (con nham nghien ctiu mot so trung binh thi thay vao dd, can cd lech chuan cua so trung binh dd) Cac y niem dUdc xay dung tti nhting nghien ctiu trUdc dd neu no' cd gid tri cho lan nghien ctiu nay, neu khong, ngudi ta phai lam tham dd trudc vdi mot phan nho cua mdu
- An dinh mot sai sd chon mdu chap nhan cho nghien ctiu, ndi khac di, phdi an dinh mot mtic y nghia nhat dinh can thiet va chap nhan dUdc cho ket qud ciia nghien ctiu day chinh la sai lam alpha can an dinh (nhu phan ldn cac nghien ctiu dich t l thong thudng, ngudi ta thudng lay mtic 5r/<) Viec an dinh mtic y nghia nhu vay cung dong nghia vdi viec an dinh mtic tin cay cua nghien ctiu 1- a.
(15)Co' dCr kien roi, chung ta se thay vao cac cong thiic cho loai m iu quyet dinh dung, se duoc cd m iu toi thieu cho nghien ciiu
b) Chon mau: Sau da quyet dinh quan the nao se dupc tien hanh nghien cUu thi die cap tot hon ck la lay m iu ngiu nhien Cac ca the dupc chon ng iu nhien vao m iu, se tranh dupc moi sai so chon vao m iu, no' cung ddni bdo rang moi ca the deu co' mot xac suat da biet dupc chon nhu nhau, dieu dd giup ta ap dung cac nguyen ly ly thuyet thong ke vao ket qua nghien cUu (thi du tinh khoang tin cay ching han)
No'i den chon m iu la ndi den nhflng se dupc chon vao m iu nghien ctiu (dap ting day du cac tieu chuan da xay dung) va nhting nguoi do' se dupc chon vao m iu nhu the nao tren nguyen tic n g iu nhien (quy dinh cac buOc chon ngiu nhien, va the thtic chon ngiu nhien cho tting buOc)
Day chinh la budc t quan trong, ma ta thudng gpi la thiet ke m iu, thuOng dupc viet duOi dang mot so de chon cac don vi m iu vao quan the nghien ctiu (hay quan the dieu tra) tti quan the dinh danh (hay quan the tham khao)
c) Xay dung quy trinh nghien ciiu.
Nghien ctiu ngang tien hanh tren quan the la mot cuoc dieu tra cong dong va quy trinh nghien ctiu la mot bo cau hoi Can ton triet de cac quy dinh viec xay dung bo cau hoi cho thong tin thu thap dupc chinh xac toi da Ngoai no' phdi cd tinh thuc thi De dam bao tinh thuc thi, phai td chtic thti thach bo cau hoi tai quan the se tien hanh dieu tra d mot quy mo nho, chinh nguOi thiet ke bo cau hoi va hoac nhting dieu tra vien se thuc hien cuoc dieu tra tien hanh, sau dd, se chinh ly cho phu hpp, ke ca ve ngdn tti, vd bo sung hoac gidm nhe bo cau hoi de dua bo cau hoi chinh thtic lam dai trd
4 T uyen ch on va huan luyen dieu tra vien.
De cho co' ket qud khach quan tin cay, cac ky thuat "lam mil" dupc ngUOi ta khuyen nen sti dung toi da co' the dupc Dieu ndy lien quan den viec tuyen chon dieu tra vien la rat quan trong: co' trinh de thuc hien tot nhting yeu cau ciia quy trinh nghien ctiu hoac bo cau hoi dat ra, nhung cung can dam bao hoi vd ghi chep lai mot cach trung thuc cac cau hoi vd trd lOi ciia tting don vi thong ke (khong tu y hoi bdng thuat ngti rieng ciia minh, khong hoi gpi y, khong hieu sai hoac dieu chinh cac trd loi theo y hieu biet ciia rieng minh )
Khong nen d ! dai thoa man viec huan luyen dieu tra vien Phdi huan luyen cho ket qud dieu tra ciia nhieu dieu tra vien khdc nhu la ciia chi mot dieu tra vien tot da tien hanh Muon dupc nhu vay, nhd nghien ctiu phdi huan luyen th at ti mi, ky luong, tting chi tiet nho m ot nhu ldi hoi, cach hoi, thai hoi, cach can do, cach ghi, cach danh dau cac ket qud trd lOi qud trinh huan luyen, phuong phap "dong vai" la khong the thieu Vd sau qua trinh dieu tra that, ho phai dupc giam sat chat che va thay the neu can
5 Lap ke h oach va to chtic trien khai thuc hien dieu tra co n g dong
Nhu tren da no'i, cac cuoc dieu tra quan the thudng sti dung m iu chum 6 day cung lay thi du sti dung m iu chum nghien ctiu Cong tic chuan bi kha dai, khong trinh bdy d day.
- Chon n g iu nhien chum
(16)khong, cd the sii dung mau 30 chum
Can can nhic day du xem chum nghien ciiu cu the dd la tap hop ca the nao, quy mo nao, thuoc mau chum dich thuc hay cai tien
Nen tim moi dieu kien de co' the chon chum vao nghien ciiu tai Ban dieu tra nghien ciiu dieu tra, tranh nhUng tien ve den dia phuong cu the
- Chon ngiu nhien don vi thong ke
Cac dieu tra vien dupc huan luyen lam theo mot cach lam thong nhat
- Tat ca moi cong viec cua dieu tra vien, tu budc chon don vi thong ke chn den moi cong viec sau dd deu phai dupc dpi ngu giam sat vien giam sat, uon nan bo sung nhat la nhUng dau trien khai cong viec NhUng Uu diem va thieu sot cua dieu tra vien phai dupc thong bao kip thdi den doi ngu dieu tra vien de phat huy hoac de cung tranh cho thong nhat toan cuoc dieu tra
6 Tap hop, xOf ly so lieu
Nen tap hpp vao cac bang tong hpp cho tUng chum, roi bang tong hpp toan bo nghien cUu, sau dd mdi xii ly
Neu xii ly tren may tinh, thi ddn gian hpn, nhung kinh nghiem da cho thay la viec vao so lieu ti mi, chinh xac la ciic ky quan trong, khau rat de nham lin, va viec phai kiem tra lai la rat khd khan, ton kem, mat nhieu thi gid Cung can neu them la ket qua da dupc xii ly theo he thong tin nao
Tren day la nhUng diem khai quat ve mot cuoc dieu tra cong dong bang mot nghien cUu ngang Tat ca nhUng bai tiep sau day se mo ta tUng buoc chu yeu ciia dieu tra cong dong
IV BAI TAP MAU CHUM Bai tap 1
Cd mot khu vUc 10 lang vdi tinh hinh dan so nhu sau:
1 iin<: I),‘in so Con}; don dan so
1 HII III 10 0
")
4011 140(1
3 2(1(1 0
4 Wo 1900
5 0 3100
(> IIIOII 4100
7 1<>0(I 5700
X 0 5900
9 350 (.25(1
10 45(1 (>700
(17)Trd lai:
- Tim khodng cach mau lang theo so dan: 6700 : = 2233
- Chon so ngdu nhien tU den 2233 (con so ngdu nhien cd chu so) Gid su so ngau nhien do' la 1814
- Vi 1900 bdt dau ldn hdn 1814, nen lang so la lang dau tien duoc chon vao mdu - Cong 1814 vdi 2233 d U d c 4047 Lang co' so ddn cong don 4100 bat dau ldn hdn 4047:
lang so la lang thU hai d U d c chon vao mdu
- Cong tiep 4047 vdi 2233 duoc 6280: lang s6 10 la lang thU ba ducic chon vao mdu Bai ta p
Muon tien hanh mdu chum, nhung lai khong biet so ddn cua tung chum, thi lam the nao? Cd U u n h U d c diem gi?
Trd lai:
- Chon lang theo mdu ngdu nhien ddn
- Chon mot ty so co dinh ho gia dinh cho moi lang (so ho dieu tra cl tUng lang se khdc nhau) - Se t khd khan viec tien hanh doi vdi dieu tra vien
- Tinh chinh xac se gidm di r a t nhieu doi vdi b d t k y U dc ludng nao Bai ta p
Tinh chinh x a c cac U dc ludng mot cuoc dieu tra phu thuoc vao nhung yeu to nao?
T lcfi:
- Cd mdu ( c a n g l d n c a n g c h i n h x a c h d n )
- So chum vd cd chum (cung cd mau thi so chum cang nhieu vdi cd chum cang nho se chinh xac hdn so chum cang it vdi cd chum cang ldn)
- Tinh bien thien ve tieu thUc nghien cUu giua cac chum vdi (tieu thUc nghien cUu d chum no khdc vdi d chum c a n g nhieu thi tinh chinh x a c cua Udc lU d n g c a n g gidm)
LAP KE HOACH VA TO CHUC MOT CUOC DIEU TRA CONG DONG
I MUC TIEU
1 Neu dUdc 10 budc lap ke hoach vd budc td chUc mot cuoc dieu tra cong dong Ra duoc nhung quyet djnh can thiet chd cuoc dieu tra
(18)II NOI DUNG
A LAP KE HOACH CHO MOT C UO C D IE U TRA.
1 B udc 1: Phat hien cac van de va nhu cau cua cong dong Cac nguyen ly chung:
TrUdc het ngudi nghien cUu phai xac dinh ro muc tieu va pham vi cua nghien ciiu bang cach:
- Xac dinh nhiing nhu cau va van de can dieu tra
- Mo ta muc tieu cua cuoc dieu tra, nhiing noi dung nao lien quan voi nhu cau cua cong dong phai diipc dieu tra
Nhieu cuoc dieu tra mac phai mot nhudc diem la tien hanh thu thap qua nhieu thong tin v'e qua nhieu van de mot cuoc dieu tra Bang moi cach phai tranh lap lai nhuoc diem
Mot cuoc dieu tra ve sUc khoe chi cd gia tri cac thong tin thu thap duoc se duoc sU dung de dap Ung mot nhu cau nao dd cua mot cong dong Cac thong tin phai de cap den khia canh tai chinh, cong viec phai lam them ciia cac can bo y te va thoi gian can thiet de tien hanh dieu tra
Cuoc dieu tra phai tra ldi cac can hoi sau:
- Benh nhan den tram y te-benh vien vi nhUng benh gi?
- Nhung thong tin hien co lieu co dai dien hay phan anh dung tinh hinh hay khdng? Neu khdng tai sao'.,
- Cd su giai thich hdp ly nao ve tinh trang benh tat hay cac nhu cau cua cong dong hay khong?
- NhUng thong tin thu thap dUdc cd the giup de giai quyet cac van die hay nhu cau cua cong dong hay khong?
- NhUng benh nhan den kham va dieu tri co dai dien cho tinh hinh benh tat va sUc khoe cua cong dong hay khong?
- (-ong dong cd duoc cung cap nhung thong tin can thiet hay khong?
- Nhung thong tin ve dan sd hoc va xa hoi hoc cd du hay khong? Con thieu nhung thong tin nao?
- NhUng nhu cau Uu tien ciia cong dong la gi?
2 B udc 2: Quyet dinh nhUng thong tin can thu thap
a) Nhiing thong tin nao la can thiet giup cho viec giai quyet nhung van de sUc khoe va nhu cau cua cong dong?
b) Nhung thong tin nao la can thiet de de xuat nhUng giai phap hay de phan bo cac nguon liic phuc vu sue khoe hay nhu cau ciia cong dong
(19)- Che an: nhUng thuc pham cd chiia protein, ngu coc, sii thay doi che an theo mua
- Nha d:
+ Loai nha, vat lieu, kien true
+ So ngudi gia dinh hien dang song dd + So phong, bep va nha ve sinh
Mot dieu quan nhat la phai liet ke mot cach ddn gian nhUng loai thong tin chinh giai doan va xem xet lai nd nhieu lan suot qua trinh lap ke hoach Dieu se giup ngudi lap ke hoach nhd thuc hien tat ca cac budc va nhung diem da dupc vach de bdo dam sU cong cua cuoc dieu tra
Ngudi thiet ke dieu tra cung phai tra ldi cac cau hoi sau: - Cuoc dieu tra se tien hanh phong van bao nhieu cau hoi
- Cac cau hoi se dupc soan thao chi tiet den dau de giai quyet nhUng vain de cua cong dong?
- N h U n g c a u h o i n a o l a q u a n t r o n g n h a t ?
3 B udc 3: Tim hieu xem nhUng thong tin can dieu tra da cd sdn hay khdng
Mot dieu quan la phai tim hieu xem nhUng thong tin nao ta can dieu tra hien da cd d trung tam y te, d bo y te, hay d cac trudng dai hoc Budc bao gom nhung cong viec sau:
- Thao luan v'e cac nhu cau cua cong dong va nhUng thong tin can thiet vdi cac nha quan ly va nhan vien y te d tuyen y te cd sd va d tuyen cao hdn
- D i e u t r a x e m n h U n g t h o n g t i n d d c d t r o n g s a c h b a o h a y c a c b a o c a o d a d u o c c o n g h o v e c a c v a n d e t U d n g t u d c a c c o n g d o n g k h a c , t r o n g k h u vU c h a y t o a n q u o c h a y k h o n g
- Kiem tra nhung thong tin hien da cd cung vdi cac nhan vien y te nhan vien d cac bo nganh khac, va d cac trudng cao dang va dai hoc
- Dieu tra xem nhung thong tin can thiet cd lien quan voi cac yeu to dac biet va dieu kien song cua nhan dan dia phuong hay khong
- N e u n g u d i d i e u t r a n h a n t h a y r a n g t h o n g t i n m a h o t h u dupc t u k i n h n g h i e m v a s a c h v d c u n g c d t h e a p d u n g dupc v d i t i n h h i n h c u a d i a p h U d n g d d , t h i h o c d t h e d i d e n m o t t r o n g h a i k e t l u a n s a u :
+ Khdng can phai tien hanh cuoc dieu tra, va nhUng thong tin hien cd du de giai quyet nhu cau s U c khoe cua cong dong
Hoac:
+ Chi can tien hanh mot cuoc dieu tra nho de thu thap nhung thong tin ma hien chua co Kinh nghiem cho thay rang thudng vdn phai tien hanh dieu tra vi nhung thong tin hien cd la chua dii va khong thich hdp
4 B udc 4: Xem xet khd nang thuc thi cong cuoc dieu tra
N g U d i d i e u t r a c a n p h a i x e m x e t c a c v a n d e s a u :
(20)- Nhung thong tin lieu vdn co' ich sau dupc thu thap va bao cao hay khong? - Cd nhUng nguon luc can thiet cho cuoc dieu tra hay khong?
Viec lap ke hoach cho mot cuoc dieu tra nho thudng la hap d in va d# tien hanh Tuy nhien, viec lap ke hoach cd the bo qua mot so van de quan hoac nhUng yeu to lam anh hudng ngupc lai den ket qud Dieu co' the khic phuc dupc neu viec lap ke hoach dupc tien hanh mot cach cd he thong, tung budc mot Ngudi lap ke hoach phai vach ro cac budc khac cua cuoc dieu tra va bao dam tung budc dupc thuc hien theo dung
ke hoach da vach
Cac van de cd lien quan den cuoc dieu tra nhu nhan luc, thdi gian va kinh phi cung phai dUPc xem xet Mot cuoc dieu tra thudng ddi hoi sU tham gia cua nhieu ngudi mot thdi gian dai Ddi vdi cac cuoc dieu tra nhd, cac nhan vien y te d tram y te hay benh vien co' the tu tien hanh dieu tra dupc nhung no' se lam tang them ganh nang cong viec hang cua ho Cuoc dieu tra cung can co' kinh phi can thiet de mua giay in bo cau hoi, va nhung van de hau can khac nhu tau xe di lai, an d cua dieu tra vien
Hau het cac cuoc dieu tra, tham chi ca nhUng cuoc dieu tra nhd, can phai dupc tien hanh nhieu thang de chuan bi, va tien hanh dieu tra tren thuc dia
Sau hoan cuoc dieu tra, cac ket qud phai dupc phdn tich va viet bao cao cung vdi ket luan Mdt so it cuoc dieu tra co' the dupc hoan mot thdi gian ngdn hon thang, nhung da sd cac cuoc dieu tra keo dai mdt nam hay hon
Trong giai doan nay, nhUng ddi hoi can thiet cho cuoc dieu tra khdng can phdi viet qua chi tiet md chi la nhung net dai cUOng de bdo ddm thuc hien cac quyet dinh da dua vd khdng quen mot chi tiet nao
Trong giai doan nay, ngudi lap ke hoach cung phdi tra ldi cac cau hoi sau: - Cd can thiet phdi thu thap cac mdu benh pham de xet nghiem hay khdng:> - Cuoc dieu tra se tien hanh bao nhieu lau?
- Nhung thong tin thu thap dupc lieu vdn cd ich lpi hoan cuoc dieu tra va viet bao cao hay khong?
- Ai se tien hanh cuoc dieu tra?
5 B udc 5: NhUng quyet dinh dau tien viec lap ke' hoach
a) Liet ke cac cau hoi chinh 111a cuoc dieu tra phdi trd ldi vd cong dong se phdi trd ldi nhung cau hoi ndy
b) Vach phuong phap (ke hoach lay m iu) can thiet de lua chon quan the va noi dieu tra