CHIS Stuies North Crolin Puli Helth A Speil Report Series y the 1908 Mil Servie Center, Rleigh, N.C. 27699-1908 www.shs.stte.n.us/schs/ No. 122 Novemer 2000 Prentl WIC Prtiiption in Reltion to Low Birth Weight n Meii Infnt Costs in North Crolin A 1997 Upte y Pul A. Buesher, Ph.D. n Stephnie J. Horton, M.S. ABSTRACT Ojetives: The purpose of this stuy is to upte n expn 1988 North Crolin evlution of prentl WIC prtiiption, while ressing some potentil methoologil issues in the erlier stuy. Methos: Meii n WIC t files were linke to 1997 North Crolin live irth reors. Among Meii irths, irth weight n Meii neworn osts were ompre etween WIC prtiipnts n WIC non-prtiipnts. Ajustments were me to ount for potentil ises ue to preterm elivery n lte entry into the WIC progrm. Results: WIC non-prtiipnts were signifintly more likely thn WIC prtiipnts to hve low-weight irths n, on verge, their neworn Meii osts were higher. These generl results persiste fter justments for the potentil ises ue to preterm elivery n lte entry into WIC. After justments, we estimte tht, overll, t lest one ollr ws sve in Meii neworn osts for every ollr spent for prentl WIC servies. Cost svings were higher for irths to minority women ompre to white women. Conlusions: The positive finings for prentl WIC prtiiption from the 1988 stuy re generlly onfirme in the present stuy. Improve helth of ies is vlule enefit resulting from the prentl WIC progrm. NORTH CAROLINA DEPARTMENT OF HEALTH AND HUMAN SERVICES
Introution The Speil Supplementl Nutrition Progrm for Women, Infnts, n Chilren (WIC) is fune y the Unite Sttes Deprtment of Agriulture n provies supplementl foo n nutrition eution to low-inome pregnnt, postprtum, or ltting women n infnts n young hilren who re nutritionlly t risk. The WIC progrm lso enourges the use of pproprite helth re. Severl previous stuies hve foun tht prentl WIC prtiiption is ssoite with improve irth outomes n reue infnt meil osts. 1,2,3,4 One of these stuies ws one in North Crolin using t on 1988 live irths to women on Meii. 1 The purpose of the present stuy is to replite n expn the 1988 North Crolin results for the 1997 irth yer, while ressing some potentil methoologil issues in the erlier stuy. Methos Meii pi lims for neworn hospitliztions were mthe to 1997 live irth ertifites to ientify the popultion of Meii irths. The Meii ID numers of these neworns were use to retrieve their meil lims pi y Meii uring the first 60 ys of life. Costs for servies eginning in the first 60 ys of life were summrize for eh Meii irth. WIC prentl reors were linke to the 1997 irth ertifites to ientify the women on Meii who prtiipte in WIC efore elivery. Using the WIC ID numers for these women, we linke to the WIC foo reemption files to etermine the te of the first reemption n the ost of foo vouhers reeeme uring the pregnny. The totl WIC prentl progrm ost ws lulte s the vlue of the foo vouhers reeeme plus nutrition servies n ministrtive osts of $9.50 per prtiipnt per month. Within the Meii irths, women prtiipting in WIC were ompre to women not prtiipting in WIC. The results re strtifie for white n minority irths, sine re is strong risk ftor for low irth weight. Approximtely 90 perent of minority irths in North Crolin re to Afrin Amerins. During 1997, the inome eligiility level for pregnnt women n their infnts for oth Meii n WIC in North Crolin ws 185 perent of the feerl poverty level. Births with no prentl re were exlue, s in the 1988 stuy, sine nerly ll woul fll in the non-wic group, resulting in poorer irth outomes in this omprison group. Multiple irths (less thn three perent of ll irths) were exlue from this stuy ue to their very high rte of low irth weight, whih oul skew the results. Births resulting in n infnt eth re inlue, unless exlue euse of no prentl re or multiple irth. Simple omprisons of low irth weight (< 2,500 grms) n very low irth weight (< 1,500 grms) were supplemente y regression nlyses, to etermine the effet of prentl WIC prtiiption on irth weight while ontrolling for other risk ftors. The ifferene in verge Meii neworn osts etween ies of prentl WIC prtiipnts n WIC non-prtiipnts ws ompre to the verge prentl WIC progrm ost, to estimte ny ost svings. The ifferene in verge Meii osts etween the WIC n non-wic groups ws lso estimte using regression nlysis, whih ontrolle for other mesurle ftors tht might impt Meii osts. Comprisons re me to the 1988 stuy with WIC prtiiption efine s one or more WIC enounters uring the prentl perio. The erlier stuy reognize tht if womn oes not enter WIC until very lte in pregnny, there is high proility she will hve norml irth weight y just ue to the length of gesttion, yet she is ounte in the WIC group. The 1988 stuy ttempte to ontrol for this is y ounting women who strte WIC fter 36 weeks gesttion in the non-wic group. This pproh i not lter the results sustntilly. In the present stuy we e nlyses to ress this issue, opting more stringent riterion where women who strte WIC t 33 or more weeks of gesttion were ounte in the non-wic group. Leving these moertely preterm irths (33 to 36 weeks) in the WIC group might fvor positive CHIS Stuy No. 122 2
fining for prentl WIC prtiiption, sine some of these irths oul hve reltively high irth weights. Another potentilly serious prolem in evlutions of prentl servies is the preterm elivery is. Women who hve very erly elivery my never hve hne to enroll in WIC. One stuy 5 use ohort nlyses to ress this prolem n we hve opte tht pproh here. Three ohorts were efine (29, 33, n 37 weeks gesttion) n the logisti regression nlyses for low irth weight n very low irth weight were repete with ll irths ourring efore the speifie week of gesttion exlue from the nlysis. This pproh mesures the effet of prentl WIC prtiiption on irth weight only for those pregnnies with gesttionl ge greter thn or equl to the utoff point. Finlly, to ress possile gesttionl ge is, we repete some of the regression nlyses using weeks of gesttion s ontrol vrile in the moel. This pproh will estimte the effet of WIC on irth weight, ontrolling for gesttionl ge. Tht is, estimte oeffiients n e interprete s the effet of prentl WIC prtiiption on irth weight t given gesttion. Results Tle 1 shows tht, mong 1997 Meii irths in North Crolin, women who prtiipte in WIC uring the prentl perio h signifintly lower Tle 1. Perentges of low n very low irth weight n selete mternl prentl risk ftors mong live irths to North Crolin women reeiving Meii enefits in 1997 y re n mternl prtiiption in the Speil Supplementl Nutrition Progrm for Women, Infnts, n Chilren (WIC) Totl White Minority WIC non-wic WIC non-wic WIC non-wic Risk ftor (n=33,080) (n=10,196) (n=17,481) (n=6,529) (n=15,599) (n=3,667) Low irth weight <2500 g 8.8 10.5* 6.9 8.4* 10.9 14.2* <1500 g 1.5 2.5* 0.9 2.0* 2.1 3.5* Mternl risk ftors Unmrrie 61.8 45.5 45.3 33.3 80.2 67.1 Eution<12 yers 40.8 37.0 45.5 40.4 35.7 30.9 Age<18 yers 12.0 7.8 10.4 7.6 13.7 8.0 Previous fetl eth or live 27.4 27.0 25.4 24.6 29.7 31.2 orn who ie Less thn equte prentl 30.3 35.9 26.1 30.6 35.1 45.4 re Smoke igrettes 23.9 22.4 32.2 25.4 14.6 17.1 One or more meil risk 33.2 31.5 30.0 29.0 36.9 36.0 ftors on irth ertifite No Meii se 41.4 82.5 47.9 87.8 34.1 73.1 mngement Births to mothers who reeive no prentl re n multiple irths re exlue. Mother ws WIC prtiipnt t some time uring pregnny. Aequy of prentl re etermine using the Kessner inex. These risk ftors inlue nemi, ri isese, ietes, hypertension, elmpsi, renl isese, n previous preterm infnt (sme s in 1988 stuy). *Signifint (P<.001) ifferene etween WIC n non-wic groups. CHIS Stuy No. 122 3
rtes of low n very low irth weight thn women who i not prtiipte in WIC. The women who prtiipte in WIC were more likely thn those who i not prtiipte to e unmrrie, of low eution, n uner ge 18. Also, the WIC group ws sustntilly more likely to hve quntittively equte level of prentl re n to hve reeive Meii se mngement servies uring pregnny. The logisti regression nlyses in Tle 2 onfirm the finings from Tle 1 of lower rtes of low n very low irth weight mong the WIC irths. Women who i not prtiipte in WIC hve n os of low irth weight 1.36 times tht of the women who i prtiipte in WIC, ontrolling for other risk ftors for low irth weight. The juste os rtio for very low irth weight for the WIC non-prtiipnts ws 1.90. An orinry lest squres regression with grms of irth weight s ontinuous epenent vrile lso showe sttistilly signifint positive effet for WIC. After ontrolling for the risk ftors shown in Tle 2, WIC non-prtiiption ws ssoite with n verge 61 grms lower irth weight (p=.0001). Tle 3 suggests tht $1.99 ws sve in neworn Meii osts (for servies eginning within 60 ys of irth) for every ollr spent y WIC in the prentl perio. These ost svings figures re $1.44 for white irths n $4.02 for minority irths. Using regression nlysis to etermine n juste ost ifferene etween WIC n non-wic irths proues higher ost svings estimtes for white n totl Meii irths (Tle 3, lst olumn). This hnge is onsistent with the fining tht the WIC group is t higher risk for low irth weight on severl of the emogrphi hrteristis; justing for these hrteristis in effet reues the ost estimtes for the WIC group. Tle 2. Ajuste os rtios (ORs) from logisti regression n 95% onfiene intervls (CIs) for selete mternl risk ftors for low irth weight mong 42,965 live irths to North Crolin women reeiving Meii enefits in 1997 Low Very low irth weight irth weight (<2500 g) (<1500 g) Risk ftors OR CI OR CI One or more meil risk 2.66 2.49, 2.85 4.71 4.02, 5.53 ftors on irth ertifite Minority sttus 1.63 1.51, 1.76 1.85 1.57, 2.19 Smoke igrettes 1.68 1.55, 1.80 1.29 1.09, 1.54 Not enrolle in WIC 1.36 1.26, 1.48 1.90 1.61, 2.25 Previous fetl eth or live 1.22 1.13, 1.31 1.50 1.28, 1.75 orn who ie Age <18 yers 1.12 1.00, 1.25 1.36 1.05, 1.76 No Meii se 0.98 0.91, 1.06 1.14 0.97, 1.34 mngement Less thn equte 1.21 1.13, 1.30 1.04 0.89, 1.22 prentl re Eution <12 yers 1.15 1.07, 1.24 0.91 0.77, 1.08 Unmrrie 1.13 1.04, 1.22 1.22 1.03, 1.45 Births to mothers who reeive no prentl re n multiple irths re exlue. Reors with missing vlues for ny vrile re exlue. These risk ftors inlue nemi, ri isese, ietes, hypertension, elmpsi, renl isese, n previous preterm infnt (sme s in 1988 stuy). Mother ws not enrolle in WIC t ll uring pregnny. Aequy of prentl re etermine using the Kessner inex. CHIS Stuy No. 122 4
Tle 3. Averge osts to Meii for neworn servies eginning within 60 ys of irth n verge osts of WIC servies for 44,409 infnts orn to North Crolin women reeiving Meii enefits in 1997 y re n mternl prtiiption in the Speil Supplementl Nutrition Progrm for Women, Infnts, n Chilren (WIC) Meii osts ($) Ajuste Ajuste WIC osts Benefit to enefit to WIC non-wic Differene ifferene ($) ost rtio e ost rtio f White 2,354 2,702 348 462 242 1.44 1.91 Minority 3,085 4,005 920 901 229 4.02 3.93 Totl 2,699 3,170 471 628 236 1.99 2.66 Births to mothers who reeive no prentl re n multiple irths re exlue. Mother ws WIC prtiipnt t some time uring pregnny. Bse on multiple regression nlysis, ontrolling for other preitors of ost shown in Tle 2. WIC osts inlue ministrtive n foo osts. e Differene ivie y WIC osts. f Ajuste ifferene ivie y WIC osts. Tles 4, 5, n 6 repet these nlyses where irths with WIC prtiiption eginning t 33 or more weeks of gesttion were ounte in the non-wic group. As expete, the ifferenes re reue. Tle 4 shows tht women who prtiipte in prentl WIC y 33 weeks of gesttion generlly h signifintly lower rtes of low irth weight n very low irth weight thn women who i not prtiipte in WIC or egn WIC lte in pregnny. Only the very low irth weight ifferene for minority irths ws not sttistilly signifint (p<.05). Agin, the WIC group h higher perentges unmrrie, with low eution, n uner ge 18. The women who egn WIC prior to 33 weeks gesttion were onsierly more likely thn the omprison group to hve quntittively equte prentl re n reeive Meii prentl se mngement servies. The logisti regression nlyses in Tle 5 inite tht lte or no prtiiption in WIC is ssoite with higher rtes of low n very low irth weight, when other risk ftors re sttistilly ontrolle. These os rtios re sttistilly signifint. Tle 6, where WIC is efine s prtiiption y 33 weeks of gesttion, shows lower neworn ost svings ssoite with WIC, ompre with Tle 3. The verge WIC progrm osts re somewht higher thn those shown in Tle 3, sine irths where WIC egn lte in pregnny re no longer inlue in the WIC group. WIC prtiiption is still ssoite with lower Meii neworn osts, ut, overll, the pprent svings re not more thn the mount expene y WIC. For totl irths, the results in Tle 6 suggest tht $0.56 ws sve in neworn Meii osts for every ollr spent y the WIC progrm for prentl servies. For minority irths, however, these results show svings in expenitures for neworn meil re of $1.26 for every ollr spent y WIC for prentl servies. Using the juste ost ifferene etween erly WIC n ll other irths (from regression nlysis), the Meii svings ssoite with WIC prtiiption re estimte t pproximtely one ollr for every ollr spent on WIC prentl servies (Tle 6, lst olumn). Tle 7 presents the juste os rtios for WIC non-prtiiption for eh of the three gesttionl ge ohorts. Among irths tht rehe 29 or 33 weeks gesttion, the os of low irth weight n very low irth weight re signifintly higher for WIC non-prtiipnts ompre to WIC prtiipnts. In the 37-week ohort, neither of the os rtios re sttistilly signifint. However, there were only 28 very low irth weight irths in this CHIS Stuy No. 122 5
Tle 4. Perentges of low n very low irth weight n selete mternl prentl risk ftors mong live irths to North Crolin women reeiving Meii enefits in 1997 y re n mternl prtiiption in the Speil Supplementl Nutrition Progrm for Women, Infnts, n Chilren (WIC) Totl White Minority Erly Lte or Erly Lte or Erly Lte or WIC no WIC WIC no WIC WIC no WIC Risk ftor (n=30,173) (n=13,103) (n=15,903) (n=8,107) (n=14,270) (n=4,996) Low irth weight <2500 g 9.0 9.6* 7.0 7.8* 11.2 12.4* <1500 g 1.6 2.1* 1.0 1.6* 2.3 2.8 Mternl risk ftors Unmrrie 61.6 49.4 45.1 36.0 80.1 71.2 Eution <12 yers 41.1 37.1 45.9 40.5 35.9 31.7 Age <18 yers 12.1 8.3 10.5 8.0 14.0 8.8 Previous fetl eth of 27.4 27.1 25.4 24.6 29.6 31.1 live orn who ie Less thn equte 29.0 37.6 25.0 31.7 33.4 47.3 prentl re Smoke igrettes 23.7 23.1 32.1 26.9 14.4 17.0 One or more meil 33.6 31.1 30.3 28.6 37.3 35.1 risk ftors on irth ertifite No Meii se 39.6 77.4 46.2 82.8 32.3 67.4 mngement Births to mothers who reeive no prentl re n multiple irths re exlue. Reors with missing vlues for ny vrile re exlue. Erly WIC mens tht the mother ws WIC prtiipnt y the 33r week of gesttion. Aequy of prentl re etermine using the Kessner inex. These risk ftors inlue nemi, ri isese, ietes, hypertension, elmpsi, renl isese, n previous preterm infnt (sme s in 1988 stuy). *Signifint (P<.05) ifferene etween WIC n non-wic groups. ohort, ompre to 742 in the full regression moels in Tles 2 n 5. The logisti regression nlyses in Tle 2 were repete, ing weeks of gesttion s ontrol vrile in the moels. For oth low irth weight n very low irth weight, the os rtios for WIC non-prtiiption were no longer sttistilly signifint. This suggests tht gesttionl ge is my e n importnt issue. Alterntively, it my e tht most of the effet of prentl WIC prtiiption in inresing irth weight is through lengthening gesttion. However, n orinry lest squres regression with grms of irth weight s ontinuous epenent vrile i show sttistilly signifint positive effet for WIC. After ontrolling for weeks of gesttion n lso the other risk ftors shown in Tle 2, WIC non-prtiiption ws ssoite with n verge 17 grms lower irth weight (p=.006). This suggests tht there is some effet of prentl WIC prtiiption in inresing irth weight t eh week of gesttion. These results re onsistent with those of the Ntionl WIC Evlution, whih foun tht prentl WIC prtiiption ws ssoite with inrese irth weight n longer urtion of gesttion. 6 CHIS Stuy No. 122 6
Tle 5. Ajuste os rtios (ORs) from logisti regression n 95% onfiene intervls (CIs) for selete mternl risk ftors for low irth weight mong 42,965 live irths to North Crolin women reeiving Meii enefits in 1997 Low Very low irth weight irth weight (<2500 g) (<1500 g) Risk ftors OR CI OR CI One or more meil risk 2.67 2.50, 2.86 4.74 4.04, 5.56 ftors on irth ertifite Blk re 1.63 1.51, 1.75 1.83 1.55, 2.17 Smoke igrettes 1.67 1.55, 1.81 1.29 1.09, 1.54 Not enrolle in WIC 1.14 1.06, 1.24 1.38 1.17, 1.62 Previous fetl eth or live 1.22 1.13, 1.31 1.50 1.28, 1.75 orn who ie Age <18 yers 1.11 0.99, 1.25 1.34 1.03, 1.74 No Meii se 1.03 0.96, 1.11 1.25 1.07, 1.47 mngement Less thn equte 1.22 1.13, 1.31 1.06 0.90, 1.24 prentl re Eution <12 yers 1.15 1.07, 1.24 0.92 0.77, 1.09 Unmrrie 1.11 1.03, 1.20 1.18 1.00, 1.40 Births to mothers who reeive no prentl re n multiple irths re exlue. Reors with missing vlues for ny vrile re exlue. These risk ftors inlue nemi, ri isese, ietes, hypertension, elmpsi, renl isese, n previous preterm infnt (sme s in 1988 stuy). Not enrolle in WIC y 33r week of gesttion. Aequy of prentl re etermine using the Kessner inex. Tle 6. Averge osts to Meii for neworn servies eginning within 60 ys of irth n verge osts of WIC servies for 44,409 infnts orn to North Crolin women reeiving Meii enefits in 1997 y re n mternl prtiiption in the Speil Supplementl Nutrition Progrm for Women, Infnts, n Chilren (WIC) Meii osts ($) Ajuste Erly Lte or Ajuste WIC osts Benefit to enefit to WIC no WIC Differene ifferene ($) ost rtio e ost rtio f White 2,397 2,550 153 233 257 0.60 0.91 Minority 3,181 3,488 307 254 243 1.26 1.04 Totl 2,768 2,907 139 240 251 0.55 0.96 Births to mothers who reeive no prentl re n multiple irths re exlue. Mother ws WIC prtiipnt y the 33r week of gesttion. Bse on multiple regression nlysis, ontrolling for other preitors of ost shown in Tle 5. WIC osts inlue ministrtive n foo osts. e Differene ivie y WIC osts. f Ajuste ifferene ivie y WIC osts. CHIS Stuy No. 122 7
Tle 7. Ajuste os rtios (OR) from logisti regression n 95% onfiene intervls (CIs) for non-wic prtiipnts mong live irths to North Crolin women reeiving Meii enefits in 1997: ohort nlyses Cohort: ll eliveries prior to speifie weeks Low irth weight Very low irth weight of gesttion re exlue OR CI OR CI Numer of irths 29 weeks 1.28 1.17, 1.39 1.66 1.30, 2.11 42,544 33 weeks 1.20 1.09, 1.31 1.57 1.02, 2.40 41,757 37 weeks 1.06 0.93, 1.22 1.81 0.77, 4.28 37,396 Mother ws not enrolle in WIC t ll fter gesttionl ge utoff. Births to mothers who reeive no prentl re n multiple irths re exlue. Sme ontrol vriles re use s in Tle 2. Reors with missing vlues for ny vrile re exlue. Disussion In the sene of rnomize stuy, it is iffiult to mesure preisely the improvements in irth outomes n svings in neworn Meii expenitures ssoite with prentl WIC prtiiption. In the regression nlyses we ontrolle for mesurle ifferenes etween the WIC n non-wic groups, ut seletion is my still result in unmesure ifferenes etween the two groups tht operte in fvor of WIC. We trie severl methos to just for possile ises ssoite with gesttionl ge, n these results generlly onfirme the positive effets of WIC foun in the initil nlyses. The inlusion of infnt eths my ffet the ost estimtes. Approximtely hlf of infnt eths our in the first y of life. Sine the non-wic group hs higher rte of low irth weight, n low irth weight ies re muh more likely to ie s infnts, the neworn osts for the non-wic group my e reue. A omprison of osts only mong surviving infnts might show lrger ost ifferene in fvor of the prentl WIC prtiipnts. This stuy onsiere ost svings only in the first 60 ys of life. Pyments for servies eginning in the first 60 ys of life were ounte, so ll of the osts of lengthy neworn hospitliztion woul e inlue. However, stuy y the Generl Aounting Offie 7 estimtes tht pproximtely 60 perent of the totl exess osts of low irth weight up to ge 18 result from the initil hospitliztion. Other signifint osts ssoite with low irth weight re rehospitliztion n other meil osts fter 60 ys of ge, long-term isility osts, n speil eution osts. These itionl osts re not mesure in the present stuy, n so the ost svings of WIC shown here likely unerestimte the totl ost svings over longer perio of time. The erlier evlution of prentl WIC prtiiption in North Crolin ws for 1988, time when the inome level for Meii eligiility for pregnnt women ws 100 perent of the feerl poverty level. In 1997, the yer of this stuy, pregnnt women were eligile for Meii t 185 perent of the feerl poverty level. As result, the numer of live irths to women enrolle in Meii nerly oule to more thn 43,000 in the present stuy. There is some eviene tht prentl WIC is CHIS Stuy No. 122 8
more effetive t the lowest inome levels. 7 The estimte WIC effets in Tles 1-3 (efore justments for preterm elivery n lte entry into the WIC) were somewht less thn the omprle effets from the 1988 stuy. The higher verge inome level of the women in the present stuy oul ontriute to this ifferene. Overll, the results here suggest tht prentl prtiiption in WIC mong women enrolle in Meii is ssoite with reue rtes of low n very low irth weight, n with lower infnt Meii osts. Cost svings were higher for irths to minority women ompre to white women. Although the methoologil iffiulties hve not een ompletely resolve, the positive finings for WIC from the 1988 stuy re generlly onfirme in this stuy. In ition to hving etter irth outomes n lower infnt osts, the women who prtiipte in WIC were more likely thn those who i not prtiipte to hve quntittively equte level of prentl re n to hve reeive Meii se mngement servies uring pregnny. The question hs een rise whether ost svings is the most pproprite riterion y whih to juge prentl re progrms. 8 It is sometimes ssume tht in orer for these progrms to e vlule, they shoul sve more thn they ost. Improve helth of mothers n ies is vlule enefit in itself n soiety shoul e willing to ommit resoures towr this gol. Aknowlegments The uthors woul like to thnk Brr Devney of Mthemti Poliy Reserh, In. n Jy Hirshmn n Jnet Shiller of the U.S. Deprtment of Agriulture for helpful omments on this pper. Referenes 1. Buesher PA, Lrson LC, Nelson MD, Lenihn AJ. Prentl WIC prtiiption n reue low irth weight n neworn meil osts: ostenefit nlysis of WIC prtiiption in North Crolin. Journl of the Amerin Dieteti Assoition 1993; 93:163-166. 2. Shrmm WF. WIC prentl prtiiption n its reltionship to neworn Meii osts in Missouri: ost/enefit nlysis. Amerin Journl of Puli Helth 1985; 75:851-857. 3. Shrmm WF. Prentl prtiiption in WIC relte to Meii osts for Missouri neworns: 1982 upte. Puli Helth Reports 1986; 101:607-615. 4. Mthemti Poliy Reserh In. The svings in Meii osts for neworns n their mothers from prentl prtiiption in the WIC progrm. Wshington D.C.: Foo n Nutrition Servie, U.S. Deprtment of Agriulture, 1990. 5. Tyson J, Guzik D, Rosenfel CR, Lsky R, Gnt N, Jiminez J, Hertwell S. Prentl re evlution n ohort nlyses. Peitris 1990; 85:195-204. 6. Rush D, Alvir JM, Kenny DA, Johnson SS, Horvitz DG. Historil stuy of pregnny outomes. Amerin Journl of Clinil Nutrition 1988; 48:412-428. 7. U. S. Generl Aounting Offie. Erly intervention: feerl investments like WIC n proue svings. April 1992. Pulition No. GAO/HRD-92-18. 8. Huntington J, Connell FA. For every ollr spent the ost-svings rgument for prentl re. The New Engln Journl of Meiine 1994; 331:1303-1307. CHIS Stuy No. 122 9
Stte of North Crolin Deprtment of Helth n Humn Servies Stte Helth Diretor A. Dennis MBrie, M.D., M.P.H. Division of Puli Helth John M. Booker, Ph.D., Diretor www.shs.stte.n.us/schs/ The NC Deprtment of Helth n Humn Servies oes not isriminte on the sis of re, olor, ntionl origin, sex, religion, ge or isility in employment or the provision of servies. Deprtment of Helth n Humn Servies 1908 Mil Servie Center Rleigh, NC 27699-1908 919/733-4728 PRESORTED STANDARD US POSTAGE PAID RALEIGH NC PERMIT #1862 500 opies of this puli oument were printe t totl ost of $121.75 or 24 per opy. 11/00 CHIS Stuy No. 122 10