2024-03-28T21:36:29Zhttp://open-archive.highwire.org/handler
oai:open-archive.highwire.org:amjepid:150/4/3272015-05-11HighWireOUPamjepid:150:4
Invited Commentary: Propensity Scores
Joffe, Marshall M.
Rosenbaum, Paul R.
COMMENTARIES
The propensity score is the conditional probability of exposure to a treatment given observed covariates. In a cohort study, matching or stratifying treated and control subjects on a single variable, the propensity score, tends to balance all of the observed covariates; however, unlike random assignment of treatments, the propensity score may not also balance unobserved covariates. The authors review the uses and limitations of propensity scores and provide a brief outline of associated statistical theory. They also present a new result of using propensity scores in case-cohort studies.<it>Am J Epidemiol</it> 1999; 150: 327–33.
Oxford University Press
1999-08-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/150/4/327
http://dx.doi.org/10.1093/oxfordjournals.aje.a010011
en
Copyright (C) 1999, Oxford University Press
oai:open-archive.highwire.org:amjepid:150/4/3342015-05-11HighWireOUPamjepid:150:4
Recent Alcohol Intake as Estimated by the Health Habits and History Questionnaire, the Harvard Semiquantitative Food Frequency Questionnaire, and a More Detailed Alcohol Intake Questionnaire
McCann, Susan E.
Marshall, James R.
Trevisan, Maurizio
Russell, Marcia
Muti, Paola
Markovic, Nina
Chan, Arthur W. K.
Freudenheim, Jo L.
ORIGINAL CONTRIBUTIONS
Epidemiologic studies often rely on food frequency questionnaires (FFQs) to collect information on alcoholic beverage intake. However, estimation of alcohol intake using FFQs may be of some concern because of limited questions concerning alcohol intake. The authors compared estimates of alcohol intake during the 12–24 months prior to interview obtained from the Health Habits and History Questionnaire and the Harvard Semiquantitative Food Frequency Questionnaire with those from a more extensive alcohol questionnaire, the Drinking Pattern Questionnaire, among 133 healthy subjects (75 men, 58 women) aged 35–73 years, residents of western New York State. Data were collected in 1995 during two separate interviewer-administered computer-assisted interviews conducted approximately 2 weeks apart. For each questionnaire, average daily ounces (1 oz = 30 ml) of alcohol intake from alcoholic beverages were calculated as the product of the reported beverage-specific drink size (ounces) and the average daily frequency of intake multiplied by a factor representing the percentage of alcohol provided by each beverage. Estimates of total alcohol and liquor intake, but not of beer and wine intake, tended to be higher for the Drinking Pattern Questionnaire compared with the FFQs. Spearman's correlation coefficients ranged from 0.69 to 0.84. These results suggest that although the Drinking Pattern Questionnaire produced higher estimates than either FFQ, both FFQs provide a reasonable ranking of participants' alcohol intake. <it>Am J Epidemiol</it> 1999; 150: 334–40.
Oxford University Press
1999-08-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/150/4/334
http://dx.doi.org/10.1093/oxfordjournals.aje.a010012
en
Copyright (C) 1999, Oxford University Press
oai:open-archive.highwire.org:amjepid:150/4/3412015-05-11HighWireOUPamjepid:150:4
Underestimation of Risk Associations Due to Regression Dilution in Long-term Follow-up of Prospective Studies
Clarke, Robert
Shipley, Martin
Lewington, Sarah
Youngman, Linda
Collins, Rory
Marmot, Michael
Peto, Richard
ORIGINAL CONTRIBUTIONS
In prospective studies, disease rates during follow-up are typically analyzed with respect to the values of factors measured during an initial baseline survey. However, because of “regression dilution,” this generally tends to underestimate the real associations of disease rates with the “usual” levels of such risk factors during some particular exposure period. The “regression dilution ratio” describes the ratio of the steepness of the uncorrected association to that of the real association. To assess the relevance of the usual value of a risk factor during particular exposure periods (e.g., first, second, and third decades) to disease risks, regression dilution ratios can be derived by relating baseline measurements of the risk factor to replicate measurements from a reasonably representative sample of study participants after an interval equivalent to about the midpoint of each exposure period (e.g., at 5, 15, and 25 years, respectively). This report illustrates the impact of this time interval on the magnitude of the regression dilution ratios for blood pressure and blood cholesterol. The analyses were based on biennial remeasurements over 30 years for participants in the Framingham Study (Framingham, Massachusetts) and a 26-year resurvey for a sample of men in the Whitehall Study (London, England). They show that uncorrected associations of disease risk with baseline measurements underestimate the strength of the real associations with usual levels of these risk factors during the first decade of exposure by about one-third, the second decade by about one-half, and the third decade by about two-thirds. Hence, to correct appropriately for regression dilution, replicate measurements of such risk factors may be required at varying intervals after baseline for at least a sample of participants. <it>Am J Epidemiol</it> 1999; 150: 341–53.
Oxford University Press
1999-08-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/150/4/341
http://dx.doi.org/10.1093/oxfordjournals.aje.a010013
en
Copyright (C) 1999, Oxford University Press
oai:open-archive.highwire.org:amjepid:150/4/3542015-05-11HighWireOUPamjepid:150:4
Evaluation of a Population Roster as a Source of Population Controls: The Massachusetts Resident Lists
Bohlke, Kari
Harlow, Bernard L.
Cramer, Daniel W.
Spiegelman, Donna
Mueller, Nancy E.
ORIGINAL CONTRIBUTIONS
Published population rosters can serve as a convenient source of population controls. The authors evaluated one such roster, the Massachusetts Resident Lists, by estimating the completeness of the Lists and by describing the differences between persons included and not included on the Lists. The subjects were cases from three case-control studies of ovarian cancer conducted in eastern Massachusetts between 1978 and 1996. For each of the three case series, more than 90% of the cases were located on the Resident Lists. Age was one of the primary differences to emerge between cases included and not included; in the most recent case series, cases younger than age 40 years were less likely than older cases to be included on the Lists. <it>Am J Epidemiol</it> 1999; 150: 354-8.
Oxford University Press
1999-08-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/150/4/354
http://dx.doi.org/10.1093/oxfordjournals.aje.a010014
en
Copyright (C) 1999, Oxford University Press
oai:open-archive.highwire.org:amjepid:150/4/3592015-05-11HighWireOUPamjepid:150:4
Birth-Cohort Phenomenon in the Time Trends of Mortality from Ulcerative Colitis
Deled, Fabiola
Sonnenberg, Amnon
ORIGINAL CONTRIBUTIONS
It has been suggested that the mortality trends of ulcerative colitis in England and Wales are shaped by an underlying birth-cohort phenomenon. This pattern implies that exposure to an environmental risk factor early in Irfe plays a crucial role in the development of the disease. The authors tested whether the birth-cohort pattern is unique to British mortality statistics or a common feature of ulcerative colitis in western countries by using the vital statistics from England and Wales, Canada, Scotland, Switzerland, the Netherlands, and the United States. Ulcerative colitis death rates from the six countries were plotted against the periods of death or periods of birth. Mortality from ulcerative colitis increased in successive generations born throughout the second half of the 19th century. It peaked in subjects born between 1880 and 1890 and has declined since then. Strikingly similar patterns were found in the six countries and when women and men were analyzed separately. The birth-cohort pattern indicates that development of ulcerative colitis is strongly influenced by one or several environmental risk factors, which act during a short period early in life. In western countries, exposure to this risk has changed in a similar fashion. <it>Am J Epidemiol</it> 1999; 150: 359–66.
Oxford University Press
1999-08-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/150/4/359
http://dx.doi.org/10.1093/oxfordjournals.aje.a010015
en
Copyright (C) 1999, Oxford University Press
oai:open-archive.highwire.org:amjepid:150/4/3672015-05-11HighWireOUPamjepid:150:4
Plasma Selenium Levels and Risk of Hepatocellular Carcinoma among Men with Chronic Hepatitis Virus Infection
Yu, Ming-Whei
Horng, Ing-Sheng
Hsu, Kuang-Hung
Chiang, Yi-Ching
Liaw, Yun Fan
Chen, Chien-Jen
ORIGINAL CONTRIBUTIONS
Both experimental and epidemiologic studies have linked a low dietary intake of selenium with an increased risk of cancer. The authors examined the association between plasma selenium levels and risk of hepatocellular carcionoma (HCC) among chronic carriers of hepatitis B and/or C virus in a cohort of 7, 342 men in Taiwan who were recruited by personal interview and blood draw during 1988–1992. After these men were followed up for an average of 5.3 years, selenium levels in the stored plasma were measured by using hydride atomic absorption spectrometry for 69 incident HCC cases who were positive for hepatitis B surface antigen (HBsAg) and/or antibodies against hepatitis C virus (mostly HBsAg positive) and 139 matched, healthy controls who were HBsAg positive. Mean selenium levels were significantly lower in the HCC cases than in the HBsAg-positive controls (<it>p</it> =0.01). Adjusted odds ratios of HCC for subjects in increasing quintiles of plasma selenium were 1.00, 0.52, 0.32, 0.19, and 0.62, respectively. The inverse association between plasma selenium levels and HCC was most striking among cigarette smokers and among subjects with low plasma levels of retinol or various carotenoids. There was no clear evidence for an interaction between selenium and α-tocopherol in relation to HCC risk. <it>Am J Epidemiol</it> 1999; 150; 367–74.
Oxford University Press
1999-08-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/150/4/367
http://dx.doi.org/10.1093/oxfordjournals.aje.a010016
en
Copyright (C) 1999, Oxford University Press
oai:open-archive.highwire.org:amjepid:150/4/3752015-05-11HighWireOUPamjepid:150:4
Case-Control Study of Non-Hodgkin's Lymphoma among Women and Heterosexual Men in the San Francisco Bay Area, California
Holly, Elizabeth A.
Lele, Chitra
Bracci, Paige M.
McGrath, Michael S.
ORIGINAL CONTRIBUTIONS
A population-based case-control study was conducted between 1988 and 1995 in the San Francisco Bay Area of California to determine risk factors for non-Hodgkin's lymphoma. Participants completed in-person interviews, and Wood was drawn to test for viruses and lymphocyte subsets. This report includes data for 1, 281 cases and 2, 095 controls. In multivariate analyses, the factors associated with a decreased risk for non-Hodgkin's lymphoma were allergy to plants, bee and wasp stings, five or more vaccinations, drugs to lower blood cholesterol, nonsteroidal anti-inflammatory drugs, total number of sexual partners, and lifetime marijuana use, whereas an increased risk was associated with cimetidine and other histamine H<inf>2</inf>-receptor antagonists, splenectomy, gonorrhea, and body mass index. Unique to sex-specific models was an increased risk for endocrine gland disorders among women and for polio among men. Median CD3, CD4, CD8, CD20, and lymphocyte counts for non-Hodgkin's lymphoma patients were significantly lower than those for controls. These results implicate environmental factors that may influence the early stages of lymphomagenesis by stimulating the immune system. Antigen-driven B cells that accumulate to form lymphoma may be suppressed by immunologic stresses such as exposure to an increased number of sexual partners and to certain medications. A history of allergies provides evidence for a persistent capacity for B-cell differentiation and therefore a decreased accumulation of B cells. The decreased risk for non-Hodgkin's lymphoma with use of nonsteroidal anti-inflammatory drugs and cholesterol-lowering drugs is consistent with a macrophage inflammatory role in B-cell proliferation. <it>Am J Epidemiol</it> 1999; 150: 375–89.
Oxford University Press
1999-08-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/150/4/375
http://dx.doi.org/10.1093/oxfordjournals.aje.a010017
en
Copyright (C) 1999, Oxford University Press
oai:open-archive.highwire.org:amjepid:150/4/3902015-05-11HighWireOUPamjepid:150:4
Body Mass index and Colon Cancer in a National Sample of Adult US Men and Women
Ford, Earls S.
ORIGINAL CONTRIBUTIONS
The evidence supporting obesity as a risk factor for colon cancer remains inconclusive, especially among women. The author studied the association between obesity and colon cancer in a nationally representative cohort of men and women aged 25–74 years who participated in the First National Health and Nutrition Examination Survey from 1971 to 1975 and were subsequently followed up through 1992. Among the 13, 420 persons included in the analytic sample, 222 incident cases of colon cancer were identified. Height and weight were measured during the baseline examination. Compared with participants whose body mass index was less than 22 kg/m2, the hazard ratios were 1.79 (95% confidence interval (Cl): 0.87, 3.71), 1.86 (95% Cl: 0.86, 4.03), 2.47 (95% Cl: 1.14, 5.32), 3.72 (95% Cl: 1.68, 8.22), and 2.79 (95% Cl: 1.22, 6.35) for participants with a body mass index of 22-<24 kg/m2, 24-<26 kg/m2, 26-<28 kg/m2, 28-<30 kg/m2, and ≥30 kg/m2, respectively. The hazard ratios were similar for men and women. Subscapular skinfold thickness, but not triceps skinfold thickness, was positively associated with colon cancer incidence among men but not women, after adjustment for body mass index and other possible confounders. These results strongly support the hypothesis that excess body weight is a risk factor for colon cancer among both men and women. <it>Am J Epidemiol</it> 1999; 150: 390–8.
Oxford University Press
1999-08-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/150/4/390
http://dx.doi.org/10.1093/oxfordjournals.aje.a010018
en
Copyright (C) 1999, Oxford University Press
oai:open-archive.highwire.org:amjepid:150/4/3992015-05-11HighWireOUPamjepid:150:4
Consequences of the Use of Different Measures of Effect to Determine the Impact of Age on the Association between Obesity and Mortality
Stevens, June
Cai, Jianwen
Juhaeri,
Thun, Michael J.
Williamson, David F.
Wood, Joy L.
ORIGINAL CONTRIBUTIONS
The impact of using different measures of the effect of obesity on mortality across age groups has not been explored. The authors examined this issue by using mortality data from 62, 116 men and 262, 965 women in the Cancer Prevention Study-I (1960–1972). Measures of effect were calculated separately, by decade of age, for five groups of participants aged 30–79 years. The rate ratio associated with obesity declined with age, from 2.60 (men) and 1.99 (women) for participants aged 30-39 years to 1.24 (men) and 1.15 (women) for those aged 70–79 years. In contrast, the rate differences between obese and reference-weight participants increased with age, from 201 (men) and 112 (women) deaths per 100, 000 person-years for those in the youngest decade to 1, 379 (men) and 626 (women) deaths per 100, 000 person-years for those in the oldest decade. The years of life lost attributable to obesity tended to increase with age but declined for those in the oldest decade. The rate advancement period declined with decade of age. Standardization of estimates to a population changed some age-associated trends. The direction of trends varied regarding the effect of obesity on mortality across age groups, depending on the measure of effect used. <it>Am J Epidemiol</it> 1999; 150: 399–407.
Oxford University Press
1999-08-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/150/4/399
http://dx.doi.org/10.1093/oxfordjournals.aje.a010019
en
Copyright (C) 1999, Oxford University Press
oai:open-archive.highwire.org:amjepid:150/4/4082015-05-11HighWireOUPamjepid:150:4
Physical Activity and Cardiovascular Disease Risk in Middle-aged and Older Women
Sesso, Howard D.
Paffenbarger, Ralph S.
Ha, Tina
Lee, I-Min
ORIGINAL CONTRIBUTIONS
The authors investigated the relation between physical activity and cardiovascular disease (CVD) in women by following 1,564 University of Pennsylvania alumnae (mean age, 45.5 years), initially free of CVD, from 1962 until 1993. Energy expenditure was estimated from the daily number of flights of stairs climbed and blocks walked as well as the sports played and was categorized into approximate thirds (<500, 500–999, ≥1,000 kcal/week). During 35,021 person-years, 181 CVD cases were identified. After adjustment for coronary risk factors, the relative risks of CVD were 0.99 (95% confidence interval (Cl): 0.69, 1.41) and 0.88 (95% Cl: 0.62, 1.25) for women who expended 500–999 and ≥1,000, respectively, compared with <500 kcal/week (<it>p</it> for trend = 0.45). Only walking was found to be inversely related to CVD risk (<it>p</it> for trend = 0.054). Compared with women who walked <4 blocks/day, the relative risks of CVD were 0.84 (95% Cl: 0.59, 1.19) and 0.67 (95% Cl: 0.45, 1.01) for women who walked 4–9 and ≥10 blocks/day, respectively. Finally, an interaction (<it>p</it> = 0.023) between body mass index and physical activity on CVD risk was observed, with an inverse association only for leaner (<23 kg/m2) women. These data showed no overall association of physical activity with CVD risk in women. However, walking ≥10 blocks/day (approximately 6 miles (9.7 km)/week) was associated with a 33% decreased risk. One explanation for this finding may be that walking was reported more precisely than other kinds of activities.<it>Am J Epidemiol</it> 1999; 150: 408–16.
Oxford University Press
1999-08-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/150/4/408
http://dx.doi.org/10.1093/oxfordjournals.aje.a010020
en
Copyright (C) 1999, Oxford University Press
oai:open-archive.highwire.org:amjepid:150/4/4172015-05-11HighWireOUPamjepid:150:4
Domestic Violence in Northern India
Martin, Sandra L.
Tsui, Amy Ong
Maitra, Kuhu
Marinshaw, Ruth
ORIGINAL CONTRIBUTIONS
This study examined the prevalence and characteristics of wife abuse as reported by nearly 6,700 married men living in five districts of northern India during 1995–1996. In addition, associations between wife abuse and sociodemographic factors were investigated to enable two theoretical/conceptual perspectives regarding abuse to be evaluated: that abuse is more common among families under stress and among more “private” families. The district-specific percentages of men who reported physically abusing their wives ranged from 18% to 45%, with 18–40% of the men in each district having had nonconsensual sex with their wives and 4–9% having physically forced their wives to have sex. The authors used logistic regression analyses to control for a variety of sociodemographic variables and found positive associations between wife abuse and stress-related factors, including the husband having a low educational level, the couple living in poverty, the husband being young when he first lived with his wife, and the couple having multiple children. Contrariwise, there was no strong empirical support for the idea that wife abuse may be more common in more “private families”. <it>Am J Epidemiol</it> 1999;150:417–26.
Oxford University Press
1999-08-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/150/4/417
http://dx.doi.org/10.1093/oxfordjournals.aje.a010021
en
Copyright (C) 1999, Oxford University Press
oai:open-archive.highwire.org:amjepid:150/4/4272015-05-11HighWireOUPamjepid:150:4
RE: "BREASTFEEDING REDUCES RISK OF RESPIRATORY ILLNESS IN INFANTS"
Gordon, A. G.
LETTERS TO THE EDITOR
Oxford University Press
1999-08-15 00:00:00.0
TEXT
text/html
http://aje.oxfordjournals.org/cgi/content/short/150/4/427
http://dx.doi.org/10.1093/oxfordjournals.aje.a010022
en
Copyright (C) 1999, Oxford University Press
oai:open-archive.highwire.org:amjepid:150/4/428-a2015-05-11HighWireOUPamjepid:150:4
RE: "DISTINGUISHING THE EFFECTS OF MATERNALAND OFFSPRING GENES THROUGH STUDIES OF 'CASE PARENT TRIADS'" AND " A NEW METHOD FOR ESTIMATING THE RISK RATIO IN STUDIES USING CASE PARENTAL CONTROL DESIGN"
Weinberg, Clarice R.
Wilcox, Allen J.
LETTERS TO THE EDITOR
Oxford University Press
1999-08-15 00:00:00.0
TEXT
text/html
http://aje.oxfordjournals.org/cgi/content/short/150/4/428-a
http://dx.doi.org/10.1093/oxfordjournals.aje.a010024
en
Copyright (C) 1999, Oxford University Press
oai:open-archive.highwire.org:amjepid:150/4/4282015-05-11HighWireOUPamjepid:150:4
THE SECOND AUTHOR REPLIES
Samet, Jonathan
LETTERS TO THE EDITOR
Oxford University Press
1999-08-15 00:00:00.0
TEXT
text/html
http://aje.oxfordjournals.org/cgi/content/short/150/4/428
http://dx.doi.org/10.1093/oxfordjournals.aje.a010023
en
Copyright (C) 1999, Oxford University Press
oai:open-archive.highwire.org:amjepid:150/4/4292015-05-11HighWireOUPamjepid:150:4
RE: "IS THERE REALLY A HETEROSEXUAL AIDS EPIDEMIC IN THE UNITED STATES? FINDINGS FROM A MULTISITE VAUDATION STUDY, 1992-1995"
Brody, Stuart
Potterat, John J.
LETTERS TO THE EDITOR
Oxford University Press
1999-08-15 00:00:00.0
TEXT
text/html
http://aje.oxfordjournals.org/cgi/content/short/150/4/429
http://dx.doi.org/10.1093/oxfordjournals.aje.a010025
en
Copyright (C) 1999, Oxford University Press
oai:open-archive.highwire.org:amjepid:150/4/430-a2015-05-11HighWireOUPamjepid:150:4
RE: "WEIGHT HISTORY, GLUCOSE INTOLERANCE, AND INSULIN LEVELS IN MIDDLE-AGED SWEDISH MEN"
Longnecker, Matthew P.
Michalek, Joel E.
LETTERS TO THE EDITOR
Oxford University Press
1999-08-15 00:00:00.0
TEXT
text/html
http://aje.oxfordjournals.org/cgi/content/short/150/4/430-a
http://dx.doi.org/10.1093/oxfordjournals.aje.a010027
en
Copyright (C) 1999, Oxford University Press
oai:open-archive.highwire.org:amjepid:150/4/4302015-05-11HighWireOUPamjepid:150:4
THE FIRST AUTHOR REPLIES
Klevens, R. Monina
LETTERS TO THE EDITOR
Oxford University Press
1999-08-15 00:00:00.0
TEXT
text/html
http://aje.oxfordjournals.org/cgi/content/short/150/4/430
http://dx.doi.org/10.1093/oxfordjournals.aje.a010026
en
Copyright (C) 1999, Oxford University Press
oai:open-archive.highwire.org:amjepid:150/4/4312015-05-11HighWireOUPamjepid:150:4
THE AUTHORS REPLY
Carlsson, Sofia
Persson, Per-Gunnar
Grill, Valdemar
LETTERS TO THE EDITOR
Oxford University Press
1999-08-15 00:00:00.0
TEXT
text/html
http://aje.oxfordjournals.org/cgi/content/short/150/4/431
http://dx.doi.org/10.1093/oxfordjournals.aje.a010028
en
Copyright (C) 1999, Oxford University Press
oai:open-archive.highwire.org:amjepid:150/4/4322015-05-11HighWireOUPamjepid:150:4
RE: "DIETARY FLAVONOID INTAKE AND RISK OF CARDIOVASCULAR DISEASE IN POSTMENOPAUSAL. WOMEN"
ERRATUM
Oxford University Press
1999-08-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/150/4/432
http://dx.doi.org/10.1093/oxfordjournals.aje.a010029
en
Copyright (C) 1999, Oxford University Press