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once child family policy, BMJ, 319, 992 - 994. The completeness of death registration in 5. Lumbiganon, P., Panamonta, M . , T h a i l a n d : E v i d e n c e f r o m D e m o g r a p h i c Laopaiboon, M., Pothlnam, S. and Patlthat, N Surveillance System of Kanehanaburi Project, (1990). Why are Thai official perinatal and infant W ° ' ' ' ^ health & Population, 1 - 9. ">'S '•-
mortality rates so low?. International Journal of 9. WB (2001). Vietnam Growing Healthy: A Epidemiology, 1 9 , 9 9 7 - 1000. Review of Vietnam' Health Sector, World Bank,
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Summary
VALIDITY OF DEATH REPORTING AND REGISTRATION OF ROUTINE SYSTEM IN BAVI DISTRICT, HATAY PROVINCE
Objectives: To examine the validity of mortality estimates collected by different methods within the study site. Method: The study was completed by comparing deaths detected and registered by different methods. Results: Out ef 471 deaths detected by all methcds in 1999 and 2000, the FilaBavi quarterly household follow - ups detected 470 deaths (99.8%). The Commune Population Registry System missed 89 cases (18.9%), the majority being infants deaths. The FilaBavi re - census survey missed 19 deaths (4%), and the neighbourhood survey, where groups of local people listed deaths, over - reported deaths.
Conclusions: Mortality estimates based on information from routine systems at the commune level have low validity. FilaBavi performed better than any of these official systems.
Keywords: Mortality validity, vital events registration, Vietnam
TY SO GlOfI KHI SINH QUA DIEU TRA THEO DOI DOC TAI HUYEN BA VI TL/ 2000 - 2009
Nguyin Dffe H l n h \ Tran Khanh T o a n \ Nguyen Hoang Long^
'Trudng Dai hoc Y Ha Ndi; -Bd Y te
Trong nhdng nam gan diy, ty sd gidi tinh khi sinh (SRB) d Viet Nam dang trd nen mat cin b'ang. Muc tieu: md ta thdc trang va xu hudng thay doi SRB cung mot sd yeu td lien quan tai huyen Ba VI td 2000 - 2009. Ddi tuang va phuang phap nghien ciifu: thdng tin cua 8608 tre sinh sdng duac ghi nhin qua dieu tra phone van ho gia dinh hang quy tai ca sd thdc dia dich ti hoc FilaBavi td 2000 - 2009. Ket qua: SRB trung binh trong 10 nam la 114,6 (dao ddng td 104,8 - 129,4), cao han nhieu so vdi mde cin bang sinh hoc va
dang cd xu hddng tang SRB dddng nhd cao han d nhdng ba me tren 35 tuoi, cd trlnh dp hoc van cao, lam vi$c trong linh vdc phi ndng nghiep. Ty so nay tang theo thd td sinh, nhat la con thd 3 trd len (120,9) va trddc do chda cd con trai (122,9). Ket luan: sd mi't can bang SRB d Ba Vi dang d mde ding bao ddng Can phai cd mdt nghien cdu sau han vS SRB lien quan de'n hanh vi Ida chon gidi tinh, tren mot pham vi rdng han.
Tff khoa: Ty sd gidi khi sinh; khu vffc nong thon
LDATVANDE
Ty sd gidi khi sinh la mpt trong nhflng ehi sd phan anh sfl can bang ve gidi eua eau true dan sd, difdc x l c dinh bang sd tre nam difpe sinh ra tren 100 tre nfl. Ty sd nay tifdng ddi dn djnh vdi mfle ehuan sinh hpe la 104 - 106/100 [2]. Mat can bang ve gidi tinh khi sinh se pha vd tfnh b i n vflng eua c l u true dan sd va gay nen nhflng he luy v l mat xa hpi khdng chi trifdc mat va ca trong tifdng lai. Tam ly chuong con trai, chinh sleh han che mde sinh eung vdi kha nang p h l t hien gidi tinh qua sieu am va de dang tiep can vdi eae dich vu nao p h i thai la nhflng nguyen nhan cd b i n d i n den tinh trang mat can bang gidi tinh dang trd nen ngay ngay sau sac d n h i l u nflde chau A nhif Han Qudc, Trung Qudc va An Dp [2, 3, 6]. 0 nflde ta, n h i l u b i o d o d i l u tra nghien cflu gan day da eho tha'y tinh trang mat can bang gidi tinh khi sinh dang d mde dang b i o dpng ddi hdi phai ed nhflng bien phap can thiep kjp thdi 11, 2 , 4 ] .
Cae nghien cflu v l va'n d l gidi tinh khi sinh d Viet Nam chu ye'u dfla vao cac eupc d i l u tra cat ngang ve dan sd hoac dfla vao so lieu b i o d o cua tdng cue tho'ng ke. Dupe tien hanh tren cd m l u Idn, cac nghien cflu nay cho phep dfla ra fldc doan chfnh xac v l ty sua't gidi khi sinh d cap qudc gia nhflng khdng p h i n anh dUdc thflc te' vd'n rat khac nhau d cae dia phfldng [2]. Chung tdi t i l n hanh nghien cdu nay tai co sd thflc dja FilaBavi, huyen Ba Vi, Ha Tay eu nham muc tieu: Mo ta thgc trang va xu hddng thay ddi ty sd gidi khi sinh theo thdi gian va tim hieu mdi lien quan vdi mgt sd yeu td kinh te xa hoi cua ba me tai huyen Ba Vi trong giai doan 2000 - 2009.
II. DOI TUONG vA PHUONG PHAP NGHIEN cOu
1. Thie't ke va dia ban nghien cffu
Nghien cflu theo doi dpc dfldc thflc hien tai co sd thflc dia dich t l hpe FilaBavi, huyen Ba Vi, ngoai thanh Ha Npi, tren mpt quan the gom 11089 hd gia dinh vdi 51024 dan sinh sdng dfldc theo ddi, cap nhat d c thdng tin v l nhan khau va sdc khde thdng qua phdng van hp gia dinh 3 thang/lan[5].
2. Dd^l tOdng nghien cffu va ky thuat thu thap thong tin
Dd'i tfldng cua nghien cflu la toan bp 8608 tre sinh sd'ng dflpe phat hien va dang ky quan ly tai cd sd thflc dia FilaBavi trong vdng 10 nam tO 2000 - 2009 thdng qua phdng v i n hd gia dinh theo djnh ky hang quy. Thdng tin ca nhan cua tre (ngay t h i n g nam sinh, gidi, eon thd may trong gia dinh) va eua ba me (tudi, n g h i nghiep, trinh do van hda, tinh trang hdn nhan) difpc thu thap, cap nhat dfla tren bang hdi sau dd dope nhap va lUu gifl trong he thd'ng cP sd dfl lieu chung cua cd s6 thflc dja FilaBavi.
3. XO ly sdlleu
Thdng tin phuc vu eho nghien eflu dUdc trich xua't tfl ep sd dfl lieu cua FilaBavi tren phan mem Access va dflde xfl ly bang phan mem Stata phien b i n 11.0. Kiem djnh x" va mo hinh xae suat logit dflde sd dung de kiem dinh xae sua't sinh ecn trai va md'i lien quan eua ty sd gidi khi sinh vdi mpt sd ye'u t d kinh te xa h p i . Ke't qua nghien eflu difdc trinh bay difdi dang d e bang, bieu.
III. KET QUA
Ty sd gidi khi sinh tfnh ehung cho d giai doan 2000 - 2009 la 114,6; tfl mfle tha'p nhat la 104,8 vao nam 2000 len mfle 129,4 nam 2005 va 128,4
nam 2009. Mae du ty sd gidi khi sinh dao dpng song van theo xu hfldng tang va tfl nam 2003 trd ve sau, ludn eao hdn mde sinh hpe binh thOdng (bieu do 1).
130 125 120 115 110 105 100
Ty so gidi Muc can bane
111.7 110.2
](M Q
106.5 104.8
129.4
127.1 128.4
12.0 109.5
2009 2000 2001 2002 2003 2004 2005 2006 2007 2008
Bieu do 1. Xu hudng thay ddi ty sd gidi khi sinh qua cac nam
Bang 1 cho thiy ty sd gidi tinh khi sinh cao hdn d nhCfng ba me thudc nhdm tren 35 tudi; cd trlnh do hoc vin td trung hoc phd thdng trd len hoac lam viec trong iTnh vdc phi ndng nghiep. Ty sd gidi khi sinh tang tuan td theo sd lin sinh, nhat la d nhdng trifdng hdp con thd 3 trd len, va cao han d nhdng trifdng hap chda cd con trai trddc dd. Tuy nhien nhdng khac biet nay chifa cd y nghTa thdng ke.
Bang 1. Ty sd gidi tinh khi sinh theo thong tin ca nhan ciia me
Ty sd gidi 123,1 Nam
Nhdm tudi me
< 2 0 20 - 35
144 4056
Nff 117 3592
> 3 5 396 303
112,9 130,7
< Tieu hoe 436 356 113,1
Flpc v i n eua me
THCS 2782 2485
THPT 875 751
112,0 115,4
N g h i nghiep me
> T H P T Lam rupng Khae
500 2754 1281
410 2503 1064
122,0 110,0 120,4
Con thd nhat 2015 1790 112,6
Con thd hai 1738 1525 114,0
Thd tfl sinh Con thfl ba 843 697
Da cd eon trai 345 295
120,9 118,3
Chfla cd con trai 494 402 122,9
Mac du vin cd sd bien thien theo thdi gian nhdng xu hifdng tang ty sd gidi khi sinh van rd nhat doi vdi nhCfng trddng hap con thd 3 trd len, dac biet trong 2 nam gin day nhit.
170 T6-2,9
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 N a m
Bieu do 2. Ty sd gidi tinh khi sinh theo thii tU sinh qua cac nam
IV. BAN LUAN
Nghien cdu cua chdng tdi dUpc thflc hien dfla tren so' lieu theo ddi dpc cua mpt cd sd thflc dja nen cd dp tin cay eao. So lieu cua nam 1999 khdng dupe dfla vao trong nghien cflu nay vi trpng nam dd, viee theo ddi sfl kien sinh ehi difpc bat dau to quy II. Hdn nfla n h i l u tac gia cho rang ty so' gidi tfnh khi sinh d Viet Nam chi mdi bat dau tang tfl nam 2000 [2, 4). Vdi sd Ifldng t r i dfldc ghi nhan la 8608, tuy chUa du de thflc hien cac phan tich chuyen sau song eung da tidp can cd m l u td'i thieu de cd the cho phep dUa ra Udc doan tUdng dd'i chfnh xac ve ty so' gidi khi sinh [2].
K i t q u i nghien cflu cho tha'y tuy cd sfl dao dpng kha ldn giOa cac nam song ty so gidi khi sinh dang d mfle eao va vdi xu hfldng tang la ehu dao. Ty so' gidi tinh ehung eho d giai doan cung nhu rieng eho tflng nam (trO nam 2000) deu cao hdn mfle sinh hpe binh thfldng (104 - 106). Tuy mde dp bien thien cd Idn hdn song xu hfldng thay ddi ty sdgidi khi sinh trong nghien cflu eua ehdng tdi kha tuong ddng vdi sd lieu d i l u tra eua Tdng cue thdng ke the hien trong mpt sd nghien cdu g i n day. Theo dd, ty so' gidi khi sinh eung tang
dan to nam 2000, dat dinh vao nam 2006 va giam xudng trong nam 2007, mudn hpn 1 nam so v6i nghien cdu cua ehdng tdi vi d i l u tra cua Tdng cue thdng ke sd dung sd lieu sinh cua nam trUdc [1,4].
Mae du cd m l u nhd song nghien cflu eung da dUa ra dUde mdt v i i gpi y ve mdi lien quan eua ty sd gidi khi sinh vdi mpt sd dac diem kinh te xa hpi eua ngfldi me. TifPng tfl nhfl nghien cflu cua Chris- tophe, ty sd gidi khi sinh cao hon mfle trung binh 5 nhflng ba me tre tudi, cd hpe van thap (tieu hoc trd xud'ng) [4], song trong trong. nghien cdu nay, ty le gidi tfnh khi sinh cao nhat trong nhdm ba me Idn tudi (> 35 tudi) hoae ed trinh dp van hda cao hdn (tdt nghiep trung hoc cd sd trd len). Khac biet nay ed the do khac biet trong ed ca'u tudi va nghe nghiep cua ddi tfldng trong hai nghien cdu kit hdp vdi sfl bien thien Idn eua ty sd gidi khi sinh.
Ty sd gidi khi sinh eao d nhflng ba me ldn tuoi cung phu hdp vdi sfl gia tang ty sd gidi theo thd tif sinh trong nghien cdU nay, dat mfle eao nhat d lan sinh thfl ba trd len, nha't la nhOng ngOdi chfla d con trai trflde dd. D i l u nay ngUde lai vdi nghien edu cfia tac gia Christophe [4] va tac gia Mathews [7], nhifng lai tfldng ddng vdi k i t luan tO bao cao nghien cuU
eua UNPFA nam 2009 [2]. D i l u nay eung ham y ed the cd mdi lien quan cua ty sd gidi khi sinh vdi ap life phai sinh eon trai d nhflng ba me chi ed con gai va vdi hanh vi lua chpn gidi tfnh trUdc sinh vdn da kha phd bien d mpt sd nifdc Chau A [2, 3].
V. KET LUAN
Vdi sU gia tang va duy tri ty sd gidi khi sinh cao hdn n h i l u so vdi mde binh thfldng, nghien eflu da chi ra thifc trang mat can bang v l ty sd gidi d mpt vung ndng thdn cua Viet Nam. Ty so' gidi khi sinh cao d nhflng ba me Idn tudi, cd trinh dp hoc van cao va nhflng lan sinh mudn, khi chfla cd eon trai trong nghien cdu nay ehi mang tinh gdi y. Viee giam sat, nghien cdu tren pham vi rpng hdn ve xu hudng va mdi lien quan gifla ty sd gidi khi sinh vdi hanh vi lUa chpn gidi tinh trUdc sinh la can thiet de ed nhflng bang chflng d i y du hdn v l sfl mat can bang gidi tinh khi sinh d Viet Nam.
T A I
LIEU
T H A M K H A O1. Nguyfin Viet Tie'n, Ngo Van Toan (2008).
Ty sd gidi tfnh khi sinh d Viet Nam nam 2006, Tap chf nghien cdu Y hpe, 56 (4): 1 - 5.
2. UNFPA (2009). Nhflng b i l n ddi gan day v l ty sd gidi khi sinh d Viet Nam - Tdng quan d c b i n g chflng. Ha Npi, t h i n g 8/2009.
3. Brogen AS, Shantlbala K, Rajkumarl B, Laishram J (2009). Determination of sex ratio by birth order in an urban community in Manipur, Indian J Public Health, 53 (1): 1 3 - 7.
4. Christophe ZG, Xuyen Hoang, Toan Ngo Van (2009). Recent Increase in Sex Ratio at Birth in Vietnam, PLoS One, 4 (2): 1 - 7.
5. Chuc NT, Diwan V (2003). FilaBavi, a demographic surveillance site, an epidemiological field laboratory in Vietnam, Seand j Public Health SuppI. 62: 3 - 7.
6. Chun H, Kim I H , Khang YH (2009). Trends in sex ratio at birth according to parental social positions: results from vital statistics birth, 1981 - 2004 in Korea], J Prev Med Public Health. 2009 Mar, 42 (2): 1 4 3 - 5 0 .
7. Mathews TJ, Hamilton BE (2005). Trend analysis of the sex ratio at birth in the United States, Natl Vital Stat Rep, 53 (20): 1 - 1 7 .
Summary
SEX RATIO AT BIRTH - A LONGITUDINAL SURVEY IN BAVI DISTRICT, HANOI CITY FROM 2000 - 2009
The sex ratio at birth (SRB) has recently becoming imbalaneed in Vietnam. Objective: To describe the situation and the trend of SRB and related factors at Bavi district from 2000 - 2009. Method: Data from 8608 live births identified through quarterly household interviews at FilaBavi health and demographic surveillance site from 2000 - 2009. Results: SRB has remarkably increased for the last ten years with the mean was 114.6 (fluctuated from 104.8 to 129.4), much higher than the normal level. It seemed to be higher among women who were above 35 years of age, or graduated from secondary school at least or among non - farmer women. The SRB also tended to worsen for higher birth order children with the highest ratio was found at the third or above childbirth (120.9), especially among women without previous sons (122.9). Conclusion: Results indicated the significant imbalance in SRB in Bavi and suggested suggested the need of a study on SRB in relation to the sex - selective behaviour at a broader scale.
Keywords: sex ratio at birthi, longitudinal, rural area
