SYSTEMATIC REVIEW Hispanic Mortality Paradox: A Systematic Review and Meta-Analysis of the Longitudinal Literature To investigate the possi- John M. Ruiz, PhD, Patrick Steffen, PhD, and Timothy B. Smith, PhD bility of a Hispanic mortality advantage, we conducted DESPITE A SIGNIFICANTLY a systematic review and which race and ethnicity are improved on previous reviews by meta-analysis of the pub- more disadvantaged risk factor assessed at study entry and par- using meta-analytic procedures fi lished longitudinal literature pro le, Hispanics in the United ticipants are followed longitudi- that took into account the differ- reporting Hispanic individ- States often experience similar or nally to mortality. This literature ences in available studies re- uals’ mortality from any better health outcomes across has added a wealth of data for and garding sample size, participant cause compared with any a range of health and disease against a Hispanic mortality ad- characteristics, selection criteria, other race/ethnicity. We contexts compared with non- vantage, but has failed to clarify and outcomes. searched MEDLINE, PubMed, Hispanic Whites (NHWs), an epi- the overall relationship. A number EMBASE, HealthSTAR, and demiological phenomenon com- of factors impede consensus, in- METHODS PsycINFO for published lit- monly referred to as the “Hispanic cluding differences in sample size, erature from January 1990 paradox.” Among the most salient selection criteria, methodologies, Studies were identified through to July 2010. Across 58 studies (4 615 747 features of this advantage is evi- follow-up time, statistical report- 2 techniques. First, we conducted participants), Hispanic popu- dence that Hispanics appear to live ing, and outcomes (i.e., morbidity, extensive electronic database 1--- 3 fi lations had a 17.5% lower longer than NHWs. These speci c-cause mortality, all-cause searches from January 1990 to risk of mortality compared findings are largely based on na- mortality). In addition, at least 5 July 2010, using MEDLINE, with other racial groups tional cohort data, with mortality narrative literature reviews of the PubMed, EMBASE, HealthSTAR, (odds ratio = 0.825; P < .001; data from the US Vital Statistics associated data7---11 were published and PsycINFO. January 1990 was 95% confidence interval = System used in the numerator and in the last decade, asserting the used as the beginning search date 0.75, 0.91). The difference population counts from the US level of interest but failing to pro- because of methodological in mortality risk was greater Census used in the denominator, vide an empirical test (e.g., meta- changes in the use of the terms among older populations yielding a death rate statistic. The analysis) to clarify the discrepancy. such as Hispanic in race and eth- and varied by preexisting classic explanations for these par- Hence, the current status of the nicity data collection and publica- health conditions, with ef- fi 12,13 fects apparent for initially adoxical ndings suggest that ei- Hispanic mortality paradox can tion efforts. To capture the fi healthy samples and those ther the denominator is arti cially best be described as one of great broadest possible sample of rele- fi with cardiovascular diseases. low because of Hispanics return- interest with signi cant logistical vant articles, 3 search term cate- The results also differed by ing to their countries of origin confusion. gories were used: (1) Hispanic racial group: Hispanics had before death (the “salmon bias We systematically reviewed the (Hispanic, Latino, Mexican, lower overall risk of mortality hypotheses”) or that the numera- longitudinal literature, comparing Puerto Rican, Cuban), (2) mortal- than did non-Hispanic Whites tor is not representative due to Hispanic mortality rates with those ity (mortality, death, longevity, and non-Hispanic Blacks, but the healthiest Hispanics migrating of other racial/ethnic groups and survival, life span), and (3) design overallhigherriskofmortality to the United States (the “healthy conducted a meta-analysis of the (prospective, longitudinal). Sec- than did Asian Americans. migrant hypothesis”). These available data as a definitive test ond, we manually examined the These findings provided hypotheses have been largely of whether there is a relative reference sections of past reviews strong evidence of a His- 4 panic mortality advantage, refuted. The contemporary Hispanic mortality advantage. and of studies meeting the inclu- with implications for con- overarching concern is that the Resolving the validity of the phe- sion criteria to locate articles not fi ceptualizingandaddressing statistical estimation approach nomenon would facilitate future identi ed in the database racial/ethnic health dispar- remains flawed because of un- research efforts to identify con- searches. ities. (Am J Public Health. derreporting of ethnicity on death tributing resilience factors that Published online ahead of certificates. Despite recent data might lead to targeted interven- Inclusion Criteria print January 17, 2013: suggesting that the associated tions. In the present study, we We included only published e1–e9. doi:10.2105/AJPH. error is negligible,5,6 the validity focused on all-cause mortality studies meeting the following cri- 2012.301103) of the paradox remains in ques- (death from any cause) as the teria in the meta-analysis: (1) tion due to its strong ties to this primary dependent variable and written in English or Spanish, (2) methodology. evaluated mortality within specific used a longitudinal design, and (3) One solution to these issues is to disease contexts to the extent that provided quantitative data re- examine longitudinal studies in sufficient data were available. We garding Hispanic mortality at the Published online ahead of print January 17, 2013 | American Journal of Public Health Ruiz et al. | Peer Reviewed | Systematic Review | e1 SYSTEMATIC REVIEW individual level compared with reported within studies were of the article until consensus was infection, 7% with diabetes, 5% that of other racial/ethnic groups. transformed to the natural log ORs obtained. with renal disease, and the We excluded studies in which for analyses and then transformed Aggregate effect sizes were cal- remaining 20% with a variety of the outcome was not explicitly back to ORs for interpretation. culated using random effects conditions, including liver disease stated as mortality (e.g., combined When effect size data were models following confirmation of and dementia. Research reports outcomes of morbidity and mor- reported in any metric other than heterogeneity. A random effects most often (91%) considered all- tality), studies of infant mortality, ORs or the natural log ORs, we approach yields results that gen- cause mortality, but some re- single-case designs, and reports transformed those values using eralize beyond the sample of stricted evaluations to mortality with exclusively aggregated data statistical software programs and studies actually reviewed.15 We associated with CVD (5%) or (e.g., census-level statistics). We macros (Comprehensive Meta- assumed that the results would other specific causes (4%). Only 8 included all other types of quanti- Analysis14). In many cases, we differ as a function of participant studies (14%) involved a medical tative research designs that were calculated effect sizes from fre- characteristics (i.e., age, gender) intervention21,24,25,33,35,45,62,73; longitudinal and yielded a statisti- quency data in matrixes of mor- and study design (i.e., length of most merely tracked participants’ cal estimate of the risk of mortality tality status by ethnicity. In cases follow-up). Random effects models mortality over time. Participants among Hispanic populations com- when frequency data were not take this between-studies variation were followed for an average of pared with that of other racial/ reported, we recovered the cell into account, whereas fixed effects 6.9 years (SD = 5.9; range =1 ethnic groups. There were no age probabilities from the reported models do not.16 month to 33 years). Preferred limitations other than those re- risk ratio and marginal probabili- Reporting Items for Systematic lated to studies of infant mortality. ties. Across studies, we assigned RESULTS Reviews and Meta-Analyses and However, the published literature OR values less than 1.00 to data Meta-analysis of Observational on mortality was largely skewed indicative of decreased mortality Figure 1 shows the study selec- Studies in Epidemiology guide- toward older ages, as reflected among Hispanics and OR values tion process. Statistically non- lines were adhered to in the design here. greater than 1.00 to data indica- redundant effect sizes were and reporting of this study.75,76 tive of increased mortality among extracted from 58 studies (Table Data Abstraction Hispanics relative to the compari- 1).17---74 Data were reported from Omnibus Analysis Articles were independently son group(s). 4 615 747 total participants, with Across the 58 studies, the ran- coded by 2 teams with 2 members When multiple effect sizes were an average composition of 26% dom effects weighted average each. A third independent mem- reported within a study at the Hispanic participants within stud- effect size was OR = 0.825 ber then compared the 2 ratings, same time, we averaged the values ies. The mean ages of participants (P < .001; 95% confidence inter- resolving discrepancies through (weighted by SE) to avoid violating at initial evaluation were 54.6 val [CI] = 0.75, 0.91).