Synthesising qualitative and quantitative evidence: a review of possible methods

BACKGROUND: The limitations of traditional forms of systematic review in making optimal use of all forms of evidence are increasingly evident, especially for policy-makers and practitioners. There is an urgent need for robust ways of incorporating qualitative evidence into systematic reviews. OBJECTIVES: In this paper we provide a brief overview and critique of a selection of strategies for synthesising qualitative and quantitative evidence, ranging from techniques that are largely qualitative and interpretive through to techniques that are largely quantitative and integrative. RESULTS: A range of methods is available for synthesising diverse forms of evidence. These include narrative summary, thematic analysis, grounded theory, meta-ethnography, meta-study, realist synthesis, Miles and Huberman's data analysis techniques, content analysis, case survey, qualitative comparative analysis and Bayesian meta-analysis. Methods vary in their strengths and weaknesses, ability to deal with qualitative and quantitative forms of evidence, and type of question for which they are most suitable. CONCLUSIONS: We identify a number of procedural, conceptual and theoretical issues that need to be addressed in moving forward with this area, and emphasise the need for existing techniques to be evaluated and modified, rather than inventing new approaches.     

Comorbidity in childhood in northern Ghana: magnitude, associated factors, and impact on mortality

BACKGROUND: It has been observed that in developing countries terminal illness in children under 5 yr of age is frequently characterized by comorbidity. This study seeks to quantify the co-occurrence of illness at the community level and investigates whether this co-occurrence increases the risk of mortality. We develop an appropriate measure of co-occurrence and investigate whether the comorbidity occurs by chance or whether it is due to shared risk factors. METHODS: The data used for the analysis was taken from a study carried out from 1989 to 1991 in northern Ghana on children aged 2-59 months (n = 1879). Coding for diarrhoea, pneumonia, and measles was carried out using the classification system of the WHO/UNICEF strategy for the Integrated Management of Childhood Illness; malaria was confirmed by laboratory analysis. A bivariate probit analysis was conducted to quantify comorbidity. We used an additive regression model, implemented using the Generalized Estimating Equation approach, to examine the impact on mortality. RESULTS: There is evidence of co-occurrence of diarrhoeal diseases and pneumonia, with greater comorbidity with increasing severity of disease. There is no evidence that the co-occurrence of diarrhoea with severe dehydration and severe pneumonia is characterized by a synergistic effect on mortality risk. CONCLUSIONS: Our study has shown that it is possible to have significant co-occurrence of illness at the community level. The bivariate probit procedure was easily adopted and considered appropriate for the analysis of comorbidity. The lack of suitable datasets for a more thorough analysis of comorbidity, and for the evaluation of synergistic effects on mortality, is a major limitation.     

The ethics of recruiting foreign nurses

Because they face a growing nursing shortage, many U.S. health care institutions have turned to recruiting foreign nurses. For foreign nurses, the practice is often an opportunity to make a better life for themselves and their families. And it helps solve a serious problem for the U.S. organizations involved. But the recruitment of foreign nurses raises a number of ethical questions. The first article here examines the practice as seen from three viewpoints, the global, that of the particular recruiting health care organization, and that of the recruited foreign nurse. The author concludes that the practice can be both a "blessing" and a "curse." The second article discusses the practice as seen from a Third World nation from which the United States, along with other Western countries, is recruiting nurses. The author, who formerly supported the practice, now opposes it.     

Prospective randomized controlled trial of fetal fibronectin on preterm labor management in a tertiary care center

OBJECTIVE: The purpose of this study was to investigate the effect of the rapid fetal fibronectin on the length of hospital stay and the use of preterm labor interventions in a tertiary care center. STUDY DESIGN: Women who were seen in the Labor and Delivery Unit with symptoms of preterm labor were assigned randomly to receive fetal fibronectin (n=46 women) or to preterm labor management without fetal fibronectin (n=51 women). Physicians were not blinded to the result; groups were compared. RESULTS: There was no difference between groups in demographic or obstetric characteristics, the hours spent in labor and delivery, the number of women who were admitted to the antepartum service, the length of stay, or medical interventions. When the results for women with a negative fetal fibronectin test were compared to women with a positive fetal fibronectin test, a significant difference was found in admissions to the antepartum service (P=.032) and the length of stay (P=.008). CONCLUSIONS: A negative fetal fibronectin test was associated with fewer admissions to the antepartum ward and a shorter length of stay.     

Site-specific metabolism of naphthalene and 1-nitronaphthalene in dissected airways of rhesus macaques

Studies in rodents have demonstrated the importance of cytochrome P450 monooxygenases in generating reactive metabolites that produce Clara cell injury. Pulmonary P450 activities in rodents are much higher than those in primates, raising the issue of relevance of rodent data to primates. Few studies on P450-catalyzed activation of cytotoxicants in subcompartments of primate lung have been reported. Accordingly, infant monkey airway subcompartments, including trachea, proximal, midlevel, distal airways, and parenchyma, were incubated with naphthalene or 1-nitronaphthalene to define metabolism at both high (500 microM) and low (50 microM) substrate concentrations. There was a relatively even distribution of metabolizing activities for naphthalene across subcompartments, but at high concentrations of 1-nitronaphthalene, lower airways (midlevel airway through parenchyma) showed higher bioactivation than upper airways. Dihydrodiol was the predominant water-soluble metabolite of naphthalene generated by all subcompartments, whereas covalently bound metabolites accounted for the greatest percentage of 1-nitronaphthalene metabolites, especially in lower airways. As anticipated, the amounts of metabolite covalently bound as a percentage of total metabolite formed increased dramatically with the 10-fold increase in substrate concentration. With both substrates, the formation of water-soluble metabolites was approximately 100 times less than observed previously in rodents. We conclude that 1) there are significant quantitative differences between rhesus and rodents in substrate bioactivation; 2) the distribution of metabolizing activities for naphthalene but not 1-nitronaphthalene is significantly different for rodents and primates; and 3) a very high percentage of the metabolites generated, particularly for 1-nitronaphthalene, is bound covalently to cellular proteins.     

Patterns of ecstasy use in Australia: findings from a national household survey

Aim To examine the patterns, correlates and context of ‘recent’ (preceding 12 months) ecstasy use using data from a nationally representative sample of Australians interviewed in 2001. Design Data were analysed from the 2001 National Drug Strategy Household Survey, a multi‐stage probability sample of Australians aged 14 years or older. The focus was on ecstasy use among 14–19‐year‐olds and 20–29‐year‐olds, as the prevalence of recent use is highest among these groups. Recent ecstasy users were compared to those who had not used in the preceding 12 months and those who had never tried ecstasy (‘others’) on a range of demographic and drug use variables. Comparisons were also drawn between the patterns and context of ecstasy use of the two groups of recent ecstasy users (users aged between 14–19 and 20–29 years). Findings In 2001, 6.1% of Australians aged 14 years or older reported life‐time ecstasy use, and 2.9% reported recent use. One in 10 (10.4%) of 20–29‐year‐olds and 5.0% of 14–19‐year‐olds had used ecstasy recently. Although there were few demographic differences between recent users and others, compared to those who had not recently used ecstasy, recent ecstasy users were more likely to have used a range of other drugs. Although recent ecstasy users of both age groups could be characterized as polydrug users, 20–29‐year‐old users were more likely to use other drugs concurrently with ecstasy. Conclusions Following cannabis and amphetamines, ecstasy is the third most widely used illicit drug in Australia. Other than a greater likelihood of having used other drugs, few demographic variables appear to distinguish recent ecstasy users from others. Australian users in their 20s use ecstasy within a context of greater polydrug use than those in their teens. Although most ecstasy users described a pattern of occasional use, minorities reported weekly use, and difficulties in reducing their use despite wishing to do so. There is a need to develop interventions to assist problematic ecstasy users to reduce their use should they wish to do so and to increase education about the potential risks of combining ecstasy with other drugs.     

Vascular responses to Angiotensin-(1-7) during the estrous cycle

Mesenteric arteries (230–290 μm) were isolated from virgin female rats at diestrous and proestrous phases of the estrous cycle and from ovariectomized (OVX) rats with or without estrogen (E₂) replacement (17β-estradiol, 7.5 + 5 mg pellets, 21 d release). Arteries were mounted in a pressurized myograph system. Angiotensin-(1–7) [Ang-(1–7)] concentration-dependent responses (10⁻¹⁰–10⁻⁵ M) were determined in arteries preconstricted with endothelin-1 (10⁻⁷ M). Mesenteric arteries were pretreated with the specific Ang-(1–7) antagonist, d-[Ala⁷]-Ang-(1–7) (10⁻⁷ M) to assess the Ang-(1–7) receptor-mediated dilator effect. Ang-(1–7) did not dilate mesenteric arteries from virgin rats at diestrus and placebo-treated OVX female rats as compared to the time control; however, Ang-(1–7) elicited a modest dilation at proestrus as compared to diestrus, which reached statistical significance at 10⁻⁸ M concentrations. Ang-(1–7) caused a concentration-dependent vasodilation in mesenteric arteries of females with E₂ replacement, with an EC₅₀ of 21 nM. d-[Ala⁷]-Ang-(1–7) blocked the vasodilator effect of Ang-(1–7). Our results demonstrate that during proestrus Ang-(1–7) elicits modest vasodilation as compared to diestrus, but lacks vasodilatory properties in vessels from diestrous and ovariectomized rats. Estrogen replacement restores a significant dilator response to Ang-(1–7) in OVX rats that is mediated by a d-[Ala⁷]-Ang-(1–7) sensitive site.     

Immigration and lifetime prevalence of DSM-IV psychiatric disorders among Mexican Americans and non-Hispanic whites in the United States: results from the National Epidemiologic Survey on Alcohol and Related Conditions

BACKGROUND: There exist no national prevalence data on specific DSM-IV Axis I psychiatric disorders among foreign-born and US-born Mexican Americans and non-Hispanic whites. OBJECTIVE: To present nationally representative data on the prevalence of DSM-IV lifetime psychiatric disorders among foreign-born and US-born Mexican Americans and non-Hispanic whites. DESIGN: Face-to-face survey conducted in the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions. SETTING: The United States and District of Columbia, including Alaska and Hawaii. PARTICIPANTS: Household and group-quarters residents, aged 18 years and older (n = 43 093). MAIN OUTCOME MEASURES: Prevalence of DSM-IV substance use disorders and mood and anxiety disorders. RESULTS: With few exceptions, foreign-born Mexican Americans and foreign-born non-Hispanic whites were at significantly lower risk (P<.05) of DSM-IV substance use and mood and anxiety disorders compared with their US-born counterparts. Although the risk of specific psychiatric disorders was similar between foreign-born Mexican Americans and foreign-born non-Hispanic whites, US-born Mexican Americans were at significantly lower risk (P<.05) of psychiatric morbidity than US-born non-Hispanic whites. CONCLUSIONS: Data favoring foreign-born Mexican Americans with respect to mental health may extend to foreign-born non-Hispanic whites. Future research among foreign-born and US-born Mexican Americans and the foreign-born and US-born of other origins and descents is needed to understand what appears to be the protective effects of culture and the deleterious effects of acculturation on psychiatric morbidity in the United States.