The role and limitations of retrospective investigations of factors possibly associated with the occurrence of a disease are discussed and their relationship to forward-type studies emphasized. Examples of situations in which misleading associations could arise through the use of inappropriate control groups are presented. The possibility of misleading associations may be minimized by controlli...

There are no reliable estimates of the burden of fall-related injuries in Pakistan. To assess this burden and develop an epidemiologic profile for these injuries data from the National injury Survey of Pakistan, a cross-sectional population-based survey on injuries, were analysed to determine incidence and relative risks for fall injury. The annual incidence of fall-related injuries was 8.85 pe...

OBJECTIVE To compare caretakers' perceived quality of care (PQC) for under-fives treated for malaria, pneumonia and diarrhoea by community health workers (CHWs) and primary health facility workers (PHFWs). METHODS Caretaker rated PQC for children aged (2-59) months treated by either CHWs or PHFWs for a bought of malaria, pneumonia or diarrhoea was cross-sectionally compared in quality domains...

Metrics such as relative hazards and relative risks do not account for the prevalence of a marker over time and its relation to whether and when an outcome occurs. Uncommon markers that have good predictive values and common markers that are poorly predictive may not be (clinically) useful in predicting disease and other health outcomes. Recent work by Little et al. (Am J Epidemiol. 2011;173(12...

In Part 1 of this study, the mathematical relations between micro and macro measures of effect were derived. The formulas thus obtained can be used for cross level comparisons of findings concerning the effect of some specific risk factor on, eg, mortality. The approach is illustrated by means of an empirical example relating to the association between unemployment and suicide. This relationshi...

It has been argued that assessment of interaction should be based on departures from additive rates or risks. The corresponding fundamental interaction parameter cannot generally be estimated from case-control studies. Thus, surrogate measures of interaction based on relative risks from logistic models have been proposed, such as the relative excess risk due to interaction (RERI), the attributa...

OBJECTIVE To determine if introducing age as another explanatory variable in an ecological regression model relating crude rates of cancer incidence and a deprivation index provides better results than the usual practice of using the standard incidence ratio (SIR) as the response variable, introducing the non-standardized index, and not including age in the model. METHODS Relative risks assoc...

This paper discusses the use of cancer incidence data in identification of cancer causation. Selective descriptive and analytical epidemiological studies were reviewed. These examples were taken primarily from Denmark, where the possibilities for epidemiological research are good due to the existence of many exposure and disease registers. Descriptive studies are still needed for a better under...

When estimating the absolute risk of cancer, the shape of the dose--response curve in the region of doses where actual exposure of man occurs is of crucial importance. This shape is equally important for the determination of relative risks, as in the comparison of risks from alternative energy sources. Experimental and epidemiological studies are, for various reasons, unable to give sufficientl...

BACKGROUND A growing number of European studies, particularly from Nordic countries, suggest an increased frequency of autism in children of immigrant parents. In contrast, North American studies tend to conclude that neither maternal ethnicity nor immigrant status are related to the rate of autism-spectrum disorders. AIMS To examine the hypotheses that maternal ethnicity and/or immigration a...