Non communicable disease behavioural risk factors such as
Non-communicable disease behavioural risk factors such as tobacco smoking, heavy alcohol consumption, physical inactivity, and unhealthy eating are socially patterned in high-income countries, with individuals of low socioeconomic status generally experiencing a higher burden of risk factors. However, the direction of the association between socioeconomic status and behavioural risk factors has changed over time. Unhealthy behaviours were more frequent in high socioeconomic groups at the beginning of the 20th century, but the burden later shifted towards the disadvantaged socioeconomic groups. This explains why non-communicable diseases have long been considered as “diseases of affluence”. A similar transition of the non-communicable disease burden from high to low socioeconomic groups over time has also been documented in several middle-income countries. Yet, as pointed out by Luke Allen and colleagues in , the situation is less clear in low-income and lower-middle-income countries (LLMICs), as studies in these countries are scarce and produce inconsistent results. The question of whether non-communicable diseases (and their risk factors) disproportionately affect poor individuals in the poorest countries has fuelled a vivid debate, as this situation would imply that substantial resources should be allocated to non-communicable diseases in countries with very low resources, in addition to ongoing efforts to control infectious diseases and undernutrition.
The inconsistent findings on the social patterning of risk factors in LLMICs might relate to the small numbers of studies done in these countries, the limited quality of several of them, and a number of methodological issues (eg, how to define socioeconomic status in these LLMICs and how to compare results between countries). Furthermore, the social patterning of risk factors might differ between countries according to cultural norms and traditions, particularly in LLMICs where the coelenterazine lifestyles and diet might be driven to a lesser extent by global media and trade than in high-income or middle-income countries. Finally, as the social gradient in non-communicable disease risk factors changes over time, inconsistencies can relate to the different time periods considered in the available studies.
In , Svetlana Popova and colleagues report unacceptably high global prevalence rates of alcohol use in pregnancy (9·8%) and fetal alcohol syndrome (FAS) (14·6 cases per 10 000 population) and estimate that each year 119 000 children are born with FAS. This finding is tragic because FAS is a leading cause of intellectual disability, birth defects, and developmental disorders, yet is entirely preventable. FAS is a lifelong condition which might also result in secondary disabilities including academic failure, substance misuse, mental ill-health, and contact with the law due to illegal behaviours, with huge resultant costs to our health, education, and justice sectors. Previous studies provide regional and national estimates of prevalence of alcohol use in pregnancy and FAS. One strength of the paper by Popova and colleagues is the use of a country-specific, random-effects meta-analysis to estimate prevalence by WHO region of alcohol use in pregnancy (0·2% in the Eastern Mediterranean Region to 25·2% in the European Region) and FAS (0·2 cases per 10 000 general population in the Eastern Mediterranean to 37·4 per 10 000 in the European region), and to provide the first estimates of global prevalence. Furthermore, Popova and colleagues link indicators of alcohol use in pregnancy and FAS to calculate that one in every 67 women who consume alcohol during pregnancy will have a child with FAS. The literature search was systematic, the meta-analysis carefully done, and the authors used country-specific variables in models to estimate alcohol consumption. Limitations of the Article relate to limitations of the data in the included primary studies. Few of these studies provided prevalence data that were truly population-based or national; only 16·5% of researchers used a validated method to identify the level of risk from prenatal alcohol exposure (PAE); and analysis of patterns of PAE were considered beyond the scope of the review. Timing, dose, and frequency of PAE are all important when considering the risk of FAS. We support the use of standardised, validated methods to obtain such information when asking women about their alcohol use in pregnancy. Future analysis of PAE patterns might give insights to assist clinicians in providing evidence-based advice to women and in understanding groups most at risk of having a child with FAS.