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Hispanic Origin and Neural Tube Defects in Houston/Harris County, Texas: I. Descriptive Epidemiology
Canfield, M. A.
Annegers, J. F.
Brender, J. D.
Cooper, S. P.
Greenberg, F.
ORIGINAL CONTRIBUTIONS
High prevalences of anencephaly and neural tube defects (NTDs) have recently been recorded for several Texas counties bordering Mexico. In addition, a few investigators have reported Hispanics to be at elevated risk for NTDs (anencephaly and spina bifida). Factors contributing to this risk have not been established. The authors conducted a study of NTDs in Harris County, Texas, to determine the prevalence of each defect. Prevalence was established by identifying cases among resident live births and fetal deaths (stillbirths at ≥20 weeks) occurring from April 1, 1989, through December 31, 1991. Using multiple case ascertainment methods, 59 cases of anencephaly and 32 cases of spina bifida were detected, resulting in prevalences of 3.8 (95% confidence interval 2.9–4.9) and 2.0 (95% confidence interval 1.4–2.8) per 10,000 live births, respectively. The ratio of anencephaly prevalence to spina bifida prevalence was 2:1 in 1989, 1:1 in 1990, and 3:1 in 1991, with a significant difference in 1991. The female: male prevalence ratio was 1.0 for spina bifida and 2.2 for anencephaly, and was higher still for anencephaly among non-Hispanics (prevalence ratio = 5.6). For each defect, Hispanics experienced a prevalence approximately three times that of non-Hispanics. This ethnic difference was greater for males with anencephaly and for females with spina bifida. For anencephaly, the Hispanic: white/Anglo prevalence ratio (4.2) and the African-American: white/Anglo prevalence ratio (1.9) were greatly elevated and the Hispanic: African-American prevalence ratio (2.2) was similar, relative to comparable studies from the past two decades. The prevalence of anencephaly recorded for public hospitals (7.0 per 10,000) was three times greater than that for private hospitals (2.4 per 10,000). Spina bifida figures were similar for public (prevalence = 2.2 per 10,000) and private (prevalence = 2.0 per 10,000) hospitals. A significantly higher prevalence of both defects was documented among Hispanics in Harris County. The higher anencephaly rates among Hispanics, African-Americans, and those using public hospitals in an era of NTD screening, prenatal diagnosis, and elective pregnancy termination suggest that socioeconomic and perhaps cultural/religious factors might influence the recorded birth prevalence of this defect in particular groups. <it>Am J Epidemiol</it> 1996;143:1–11
Oxford University Press
1996-01-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/143/1/1
http://dx.doi.org/10.1093/oxfordjournals.aje.a008647
en
Copyright (C) 1996, Oxford University Press
oai:open-archive.highwire.org:amjepid:143/1/101-a2015-05-11HighWireOUPamjepid:143:1
THE AUTHORS REPLY
Mares-Perlman, Julie A.
Klein, Barbara E. K.
Klein, Ronald
Brady, William E.
Palta, Mari
LETTERS TO THE EDITOR
Oxford University Press
1996-01-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/143/1/101-a
http://dx.doi.org/10.1093/oxfordjournals.aje.a008649
en
Copyright (C) 1996, Oxford University Press
oai:open-archive.highwire.org:amjepid:143/1/1012015-05-11HighWireOUPamjepid:143:1
RE: "DIET AND NUCLEAR LENS OPACITIES"
Milton, Roy C.
LETTERS TO THE EDITOR
Oxford University Press
1996-01-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/143/1/101
http://dx.doi.org/10.1093/oxfordjournals.aje.a008648
en
Copyright (C) 1996, Oxford University Press
oai:open-archive.highwire.org:amjepid:143/1/1022015-05-11HighWireOUPamjepid:143:1
RE: "THE SPECTRUM OF MEDICAL CONDITIONS AND SYMPTOMS BEFORE ACQUIRED IMMUNODEFICIENCY SYNDROME IN HOMOSEXUAL AND BISEXUAL MEN INFECTED WITH THE HUMAN IMMUNODEFICIENCY VIRUS"
Salman, M. D.
Hutchison, J. M.
Smith, M.
LETTERS TO THE EDITOR
Oxford University Press
1996-01-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/143/1/102
http://dx.doi.org/10.1093/oxfordjournals.aje.a008650
en
Copyright (C) 1996, Oxford University Press
oai:open-archive.highwire.org:amjepid:143/1/1032015-05-11HighWireOUPamjepid:143:1
THE FIRST AUTHOR REPLIES
Holmberg, Scott D.
LETTERS TO THE EDITOR
Oxford University Press
1996-01-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/143/1/103
http://dx.doi.org/10.1093/oxfordjournals.aje.a008651
en
Copyright (C) 1996, Oxford University Press
oai:open-archive.highwire.org:amjepid:143/1/1042015-05-11HighWireOUPamjepid:143:1
ERRATUM
ERRATUM
Dr. David G. Ostrow and colleagues have informed the <it>Journal</it> that a numerical error appeared in their recently published paper (1). In the abstract, the fourth line from the bottom should read “for use of cocaine, OR = 81.3 (95% confidence interval 8–824), …”. In table 3, under “<it>Post-visit 9 data (1989–1992)</it>,” models 1 and 2, the 95 percent confidence intervals for “Use Of cocaine” should be 7.78–762.37 and 8.02–824.29, respectively
Oxford University Press
1996-01-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/143/1/104
http://dx.doi.org/10.1093/oxfordjournals.aje.a008652
en
Copyright (C) 1996, Oxford University Press
oai:open-archive.highwire.org:amjepid:143/1/122015-05-11HighWireOUPamjepid:143:1
Hispanic Origin and Neural Tube Defects in Houston/Harris County, Texas: II. Risk Factors
Canfield, M. A.
Annegers, J. F.
Brender, J. D.
Cooper, S. P.
Greenberg, F.
ORIGINAL CONTRIBUTIONS
Several investigators have reported Hispanics to be at elevated risk for neural tube defects (anencephaly and spina bifida). Factors contributing to this risk have not been established. The authors conducted a case-control study of neural tube defects (NTDs) among births occurring in Harris County, Texas, from April 1, 1989, through December 31, 1991. Through the use of multiple ascertainment methods, 59 cases of anencephaly and 32 cases of spina bifida were detected. Controls (<it>n</it> = 451) were sampled for the same time period from Harris County vital records. Regardless of how Hispanic ethnicity was classified, having a Hispanic parent was a risk factor for both anencephaly and spina bifida. The primary etiologic question was whether increased NTD risk in Hispanics is explained by maternal diabetes or by other factors (e.g., maternal birthplace, prenatal care, reproductive history, age, socioeconomic status). Mexico-bom Hispanics were no more likely than Texas-bom Hispanics to deliver a fetus or infant with an NTD. Having a Hispanic mother was a risk factor for anencephaly among infants bom to women with early prenatal care (odds ratio (OR) = 4.54 95% confidence interval (Cl) 2.21–9.40) but not for those bom to latecomers. Earlier prenatal care seemed “protective” for non-Hispanics (OR = 0.18, 95% Cl 0.06–0.65) but not for Hispanics. After simultaneous adjustment for eight variables in multivariate analysis, having a Hispanic (versus non-Hispanic) mother remained a strong risk factor for both anencephaly (OR = 2.58,95% Cl 1.19–5.61) and spina bifida (OR = 3.71, 95% Cl 1.48–9.31). Any previous pregnancy termination/fetal loss was also associated with anencephaly in a final logistic regression model (OR = 2.48, 95% Cl 1.20–5.10), and having a teenage mother (aged <20 years) approached significance (OR = 2.21, 95% Cl 0.92–5.31). “Hispanic mother” was the only study variable significantly associated with spina bifida in multivariate analysis. Results for diabetes suggested no association with anencephaly (OR = 1.24, 95% Cl 0.25–6.17). An increased risk of NTDs among Hispanics remained after controlling for other factors. For anencephaly, this risk might be partially explained by economic and cultural differences between Hispanics and non-Hispanics, and the effect of these factors on rates of prenatal diagnosis and elective pregnancy termination. <it>Am J Epidemiol</it> 1996;143:12–24
Oxford University Press
1996-01-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/143/1/12
http://dx.doi.org/10.1093/oxfordjournals.aje.a008653
en
Copyright (C) 1996, Oxford University Press
oai:open-archive.highwire.org:amjepid:143/1/252015-05-11HighWireOUPamjepid:143:1
Case-Control Study of Oral Contraceptive Use and Risk of Breast Cancer
Rosenberg, Lynn
Palmer, Julie R.
Rao, R. Sowmya
Zauber, Ann G.
Strom, Brian L.
Warshauer, M. Ellen
Harlap, Susan
Shapiro, Samuel
ORIGINAL CONTRIBUTIONS
The relation of oral contraceptive use to the risk of breast cancer in white women aged 25–59 years was assessed with data collected during 1977–1992 in a case-control surveillance system in hospitals in Boston, New York, and Philadelphia. A total of 3,540 cases with breast cancer were compared with 4,488 controls with nonmalignant nongynecologic conditions unrelated to oral contraceptive use. Relative risk estimates were obtained by unconditional logistic regression with control for major risk factors. For at least 1 year of use relative to less than 1 year, the multivariate relative risk estimate was 1.7 (95% confidence interval (Cl) 1.3–2.3) in women aged 25–34 years, 0.9 (95% Cl 0.7–1.0) in women aged 35–44 years, and 1.2 (95% Cl 1.0–1.4) in women aged 45–59 years (,<it>p</it> < 0.01 for the difference across age). Among women aged 25–34 years, the relative risk estimates were greatest for use of long duration, but the trend was not statistically significant (<it>p</it> = 0.17); in addition, the duration of use was correlated with the recency of use, and it was not possible to distinguish their effects. Among women aged 35–44 years, the relative risk estimate decreased with increasing duration of use (<it>p</it> = 0.01). Among women aged 45–59 years, some relative risk estimates were increased, but there was no consistent pattern. The results add to the evidence of an association between oral contraceptive use and an increased risk of breast cancer at young ages. <it>Am J Epidemiol</it> 1996;143:25–37
Oxford University Press
1996-01-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/143/1/25
http://dx.doi.org/10.1093/oxfordjournals.aje.a008654
en
Copyright (C) 1996, Oxford University Press
oai:open-archive.highwire.org:amjepid:143/1/382015-05-11HighWireOUPamjepid:143:1
Association of Bone Mineral Density and Sex Hormone Levels with Osteoarthritis of the Hand and Knee in Premenopausal Women
Sowers, MaryFran
Hochberg, Marc
Crabbe, Jeffrey P.
Muhich, Anthony
Crutchfield, Mary
Updike, Sharon
ORIGINAL CONTRIBUTIONS
Mechanical stress on the cartilage and metabolic and/or hormonal influences have been suggested as possible etiologic factors for osteoarthritis. This paper reports findings from data collected in 1992 that were used to examine associations between osteoarthritis and risk factors in 573 Caucasian women aged 24–45 years from the Michigan Bone Health Study. Radiographs of the dominant hand and both knees were evaluated using the Kellgren and Lawrence grading scale. The prevalence of osteoarthritis (grade 2 or higher) in this population was 2.8% for hands and 3.6% for knees. Using polytomous multiple logistic regression, the authors found older age, increasing bone mineral density, and decreasing testosterone levels to be significantly associated with increasing hand scores. Older age and hand injury were significantly associated with grades of 2 or higher. Increasing osteoarthritis knee scores were associated with older age, increasing bone density, increasing body mass index, and current use of hormone replacement therapy. A knee grade of 2 or higher was associated with increasing estradiol levels, knee injury, and higher blood pressure. This study indicates that age, bone density, and injury are risk factors common to the development of hand and knee osteoarthritis in this non-elderly female population. <it>Am J Epidemiol</it> 1996;143:38–47
Oxford University Press
1996-01-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/143/1/38
http://dx.doi.org/10.1093/oxfordjournals.aje.a008655
en
Copyright (C) 1996, Oxford University Press
oai:open-archive.highwire.org:amjepid:143/1/482015-05-11HighWireOUPamjepid:143:1
Spouse Correlations in Cardiovascular Risk Factors and the Effect of Marriage Duration
Knuiman, Matthew W.
Divitini, Mark L.
Bartholomew, Helen C.
Welborn, Timothy A.
ORIGINAL CONTRIBUTIONS
Spouse correlations in cardiovascular risk factors were investigated using data on 2,836 spouse pairs collected in the Busselton Population Health Surveys over the period 1966–1981. The risk factors considered were systolic blood pressure, diastolic blood pressure, body mass index, triceps fatfold, cholesterol, and forced expiratory volume (1 second). Statistically significant positive correlations (<it>p</it> <0.01) were found for all (age-adjusted) variables. There was a statistically significant decreasing trend in the correlations for systolic blood pressure with marriage duration (trend <it>p</it> <0.01). Although no other variables showed statistically significant trends, the correlations for diastolic blood pressure (<it>p</it> = 0.29), body mass index (<it>p</it> = 0.14), and forced expiratory volume (<it>p</it> = 0.16) also decreased with marriage duration, and correlations for cholesterol (<it>p</it> = 0.61) and triceps fatfold (<it>p</it> = 0.99) increased with marriage duration. These results suggest that there is spousal concordance in cardiovascular risk factors. The lack of consistent increasing trends in the correlations with marriage duration suggests that assortative mating may be a more likely explanation than the sharing of a common environment. <it>Am J Epidemiol</it> 1996;143:48–53
Oxford University Press
1996-01-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/143/1/48
http://dx.doi.org/10.1093/oxfordjournals.aje.a008656
en
Copyright (C) 1996, Oxford University Press
oai:open-archive.highwire.org:amjepid:143/1/542015-05-11HighWireOUPamjepid:143:1
Physical Activity Levels and Changes in Relation to Longevity: A Prospective Study of Swedish Women
Lissner, Lauren
Bengtsson, Calle
Björkelund, Cecilia
Wedel, Hans
ORIGINAL CONTRIBUTIONS
In 1968–1969, a population-based sample of Swedish women aged 38–60 years was recruited for a health survey, and 20-year survival was later ascertained from national registries. Occupational and leisure-time physical activity data from the baseline and 6–year follow-up examinations were evaluated in relation to all-cause mortality among 1,405 women who were initially free of major diseases. In comparison with being inactive, the mortality relative risk associated with being somewhat active was 0.28 (95% confidence interval 0.17–0.46) for occupational activity and 0.56 (95% confidence interval 0.39–0.82) for leisure-time activity. Being in the most active occupational or leisure activity category further decreased mortality risk to a minor extent. A within-subject decrease in leisure activity over 6 years was also a significant risk factor for all-cause mortality (relative risk = 2.07, relative to no change), although there was no evidence of a benefit from increasing physical activity levels. Since exclusion of early endpoints did not affect the associations in any significant way, underlying illness is unlikely to have played a major role in these analyses. It is concluded that decreases in physical activity as well as low initial levels are strong risk factors for mortality in women, and that their predictive value persists for many years. <it>Am J Epidemiol</it> 1996;143:54–62
Oxford University Press
1996-01-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/143/1/54
http://dx.doi.org/10.1093/oxfordjournals.aje.a008657
en
Copyright (C) 1996, Oxford University Press
oai:open-archive.highwire.org:amjepid:143/1/632015-05-11HighWireOUPamjepid:143:1
Type A Behavior Pattern and Change in Blood Pressure from Childhood to Adolescence: The Minneapolis Children's Blood Pressure Study
Lee, David J.
Gomez-Marin, Orlando
Prineas, Ronald J.
ORIGINAL CONTRIBUTIONS
The association of the Type A behavior pattern with change in blood pressure was examined in a multiethnic sample of schoolchildren. Blood pressure was assessed in 1978 (mean age = 8 years) and approximately biannually thereafter through 1987–1990, when a post-high school screening was completed. The Matthews Youth Test for Health (MYTH) was completed by the teachers of a sample of participants in 1982 (<it>n</it> = 502). The Jenkins Activity Survey (JAS) was completed by all adolescents who participated in the post-high school screening (<it>n</it> = 816). Males were more likely to be classified as Type A than were females by the JAS and the MYTH. Type A status was not associated cross-sectionally with elevated blood pressure. JAS-assessed Type B males had significantly higher mean post-high school fourth- and fifth-phase diastolic blood pressures than did Type A males (70.2 mmHg vs. 68.2 mmHg, <it>p</it> < 0.05; 68.1 mmHg vs. 65.2 mmHg, <it>p</it> < 0.01). JAS-assessed Type A/B status was not associated with 10-year change in blood pressure. MYTH-determined Type B females tended to have higher diastolic blood pressures than MYTH-determined Type A females throughout the 10-year study period. Results from this study did not confirm the hypothesis that Type A participants would have significantly higher blood pressures than Type B participants at the time of Type A assessment; nor did they confirm the hypothesis that Type A participants would exhibit greater increases in blood pressure than Type B participants over a 10-year period. <it>Am J Epidemiol</it> 1996;143:63–72
Oxford University Press
1996-01-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/143/1/63
http://dx.doi.org/10.1093/oxfordjournals.aje.a008658
en
Copyright (C) 1996, Oxford University Press
oai:open-archive.highwire.org:amjepid:143/1/732015-05-11HighWireOUPamjepid:143:1
Risk Factors for Constant, Severe Trachoma among Preschool Children in Kongwa, Tanzania
West, Sheila K.
Muñoz, Beatriz
Lynch, Matthew
Kayongoya, Andrew
Mmbaga, B.B.O.
Taylor, Hugh R.
ORIGINAL CONTRIBUTIONS
Trachoma, an ocular infection caused by <it>Chlamydia trachomatis</it>, is the second leading cause of blindness worldwide. The blinding sequelae, which occur in middle age, are felt to be the result of numerous or lengthy episodes of severe inflammatory trachoma in childhood. Risk factors for constant, severe trachoma were identified in a group of children enrolled in a longitudinal study in Kongwa, Tanzania, where villages were randomized in a clinical trial of mass treatment and a behavior modification campaign. In 1989, each of 1,417 randomly selected children had photographs taken of an upper eyelid for determination of their trachoma status. The photographs were graded by a reader who was masked as to the village and date of each photograph. Risk factor data on the family's socioeconomic status, distance to water, and hygiene practices were obtained at baseline. Follow-up examinations occurred 2, 6, and 12 months from baseline. Data from all four time points were available for 82% of the children enrolled. Overall, 10% of the children had constant, severe trachoma, defined as severe trachoma at three or four examinations. The odds ratio for severe trachoma was 1.9 for female children (95% confidence interval 1.3–2.7). Familial cattle ownership and having one or more siblings with trachoma at baseline were also significantly related to the odds of having severe trachoma. Children with a sustainably clean face had lower odds (odds ratio = 0.4, 95% confidence interval 0.3–0.7). A subgroup of 10% of children in these hyperendemic communities always seemed to have severe trachoma, despite enrollment in a mass treatment campaign. Improved face-washing plus antibiotic treatment may decrease the likelihood that these children will be at risk for blinding complications in adulthood. <it>Am J Epidemiol</it> 1996;143:73–8
Oxford University Press
1996-01-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/143/1/73
http://dx.doi.org/10.1093/oxfordjournals.aje.a008659
en
Copyright (C) 1996, Oxford University Press
oai:open-archive.highwire.org:amjepid:143/1/792015-05-11HighWireOUPamjepid:143:1
T-Lymphocyte Subsets and Prolonged Diarrhea in Young Children from Guinea-Bissau
Mølbak, Kåre
Lisse, Ida M.
Aaby, Peter
ORIGINAL CONTRIBUTIONS
In a community-based prospective study of 380 children conducted between 1987 and 1990, the rate of diarrhea was significantly associated with percentage of CD8 T-lymphocytes and the CD4 : CD8 ratio. After adjustment for age and previous diarrhea, the relative incidence of diarrhea with a duration of ≥7 days was 2.10 (95% confidence interval (CO 1.15–3.85) in children with 20–29.9% CD8 T-cells and 3.41 (95% Cl 1.29–9.01) in children with 2:30% CD8 T-cells (in comparison with children who had less than 20% CD8 cells)(<it>p</it> for trend = 0.004). There was a nonsignificant tendency for rates of diarrhea of ≥7 days to decrease according to increasing proportions of CD4 cells (<it>p</it> = 0.194). The authors found no significant association between T-cell subsets and diarrhea which resolved within 6 days. The association between the incidence of prolonged diarrhea and T-cell subset proportions could not be explained as a confounding effect of low weight, breastfeeding, or previous infection with measles or <it>Cryptosporidium</it>. However, other prior infections or micronutrient deficiencies may explain the findings, and these host factors may be significant targets in intervention against diarrheal diseases. <it>Am J Epidemiol</it> 1996; 143:79–84
Oxford University Press
1996-01-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/143/1/79
http://dx.doi.org/10.1093/oxfordjournals.aje.a008660
en
Copyright (C) 1996, Oxford University Press
oai:open-archive.highwire.org:amjepid:143/1/852015-05-11HighWireOUPamjepid:143:1
Evaluation of Birth Cohort Patterns in Population Disease Rates
Tarone, Robert E.
Chu, Kenneth C.
ORIGINAL CONTRIBUTIONS
Interpretation of trends in disease rates using conventional age-period-cohort analyses is made difficult by the lack of a unique set of parameters specifying any given model. Because of difficulties inherent in age-period-cohort models, neither the magnitude nor the direction of a linear trend in birth cohort effects or calendar period effects can be determined unambiguously. This leads to considerable uncertainty in making inferences regarding disease etiology based on birth cohort or calendar period trends. In this paper, the authors demonstrate that changes in the direction or magnitude of long term trends can be identified unequivocally in age-period-cohort analyses, and they provide parametric methods for evaluating such changes in trend within the usual Poisson regression framework. Such changes can have important implications for disease etiology. This is demonstrated in applications of the proposed methods to the investigation of birth cohort trends in female breast cancer mortality rates obtained from the National Center for Healthe Statistics for the United States (1970–1989) and from the World Health Organization for Japan (1955–1979). <it>Am J Epidemiol</it> 1996;143:85–91
Oxford University Press
1996-01-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/143/1/85
http://dx.doi.org/10.1093/oxfordjournals.aje.a008661
en
Copyright (C) 1996, Oxford University Press
oai:open-archive.highwire.org:amjepid:143/1/922015-05-11HighWireOUPamjepid:143:1
Optimal Sampling Strategies for Two-Stage Studies
Reilly, Marie
ORIGINAL CONTRIBUTIONS
The optimal allocation of available resources is the concern of every investigator in choosing a study design. The recent development of statistical methods for the analysis of two-stage data makes these study designs attractive for their economy and efficiency. However, little work has been done on deriving two-stage designs that are optimal under the kinds of constraints encountered in practice. The methods presented in this paper provide a means of deriving designs that will maximize precision for a fixed total budget or minimize the study cost necessary to achieve a desired precision. These optimal designs depend on the relative information content and the relative cost of gathering the first- and second-stage data. In place of the usual sample size calculations, the investigator can use pilot data to estimate the study size and second-stage sampling fractions. The gains in efficiency that can result from such carefully designed studies are illustrated here by deriving and implementing optimal designs using data from the Coronary Artery Surgery Study (Circulation 980:62:254–61). <it>Am J Epidemiol</it> 1996:143:92–100
Oxford University Press
1996-01-01 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/143/1/92
http://dx.doi.org/10.1093/oxfordjournals.aje.a008662
en
Copyright (C) 1996, Oxford University Press