Question

A large epidemiology study has found a statistically significant association between the number of people who go to the Emergency Department with asthma attacks and the ozone concentration the preceding day. Please describe some possible factors that might confound this association and explain how these factors meet the definition of confounding.

Answer 1

Answer ;-

The role of air pollution in asthma exacerbations is less consistent than that found for chronic obstructive pulmonary disease (COPD). In a comprehensive review of all studies on hospital admissions for asthma and acute effects of daily levels of air pollution, Anderson et al found inconclusive results both in adults and children.

Additionally, the biggest board examine ever done (the PEACE ponder)— which included 28 boards in nine nations and included 2010 kids with respiratory side effects—did not discover any relationship with manifestations, capacity or medicine, which negates the discoveries of past board thinks about in asthmatic patients in connection to particles and ozone (O3).

One of the clarifications for this irregularity is an absence of measurable intensity of an uncommon wonder, for example, day by day asthma occasions. The European multicentre ponders Air Pollution Health Effects Approach (APHEA I) which incorporated a few urban communities and the bigger new examination (APHEA II)6 have defeated this restriction and detailed a relationship among molecule and nitrogen dioxide (NO2) levels and every day affirmations for asthma in grown-ups, and particles, NO2, and sulfur dioxide (SO2) levels in kids, and a relationship with O3 in a few territories.

A different explanation for the inconsistent results concerns the differences between cities in the pollution mixtures, particularly the confounding or synergistic role of pollen and spores. Some studies have addressed the potential for a confounding role by pollen and spores and have consistently found a lack of confounding effect on the association between air pollution and asthma admissions or symptoms.

Dust has once in a while been related with asthma side effects, while spore tallies have reliably been found to influence the manifestations of asthma. Tentatively, there is firm help for the speculation that O3, NO2, SO2, and particles adjust unfavorably susceptible reactions in asthmatic subjects, which has been watched for O316– 18 and NO2 in human volunteers.18– 22 However, just a couple of concentrates in genuine air have broke down the synergism between air toxins and pollen1 and parasitic spores in intensifications of asthma.

A last conceivable clarification for the conflicting outcomes emerges from the job of helplessness factors, (for example, severity23) that may improve the impact of toxins on asthma. The vast majority of the trial and epidemiological examinations in asthmatics have included subjects with moderate asthma, though extreme asthmatics seem, by all accounts, to be considerably more powerless to air contamination impacts.

some possible factors that might confound

1. The confounding factor must be associated with both the risk factor of interest and the outcome.
2. The confounding factor must be distributed unequally among the groups being compared.
3. A confounder cannot be an intermediary step in the causal pathway from the exposure of interest to the outcome of interest.

For instance, it is realized that unassuming liquor utilization is related with a diminished danger of coronary illness, and it is trusted that one of the systems by which liquor causes a lessened hazard is that liquor raises blood dimensions of HDL, the alleged "great cholesterol." Higher dimensions of HDL are known to be related with a decreased danger of coronary illness. Subsequently it is trusted that humble liquor utilization raises HDL levels, and this, thusly, decreases coronary illness. In a circumstance like this HDL levels are not confounder of the relationship among liquor and coronary illness, since it is a piece of the system by which liquor creates this gainful impact. Whenever expanded HDL is an outcome of liquor utilization and part of the component by which it brings down the danger of coronary illness, at that point it's anything but a confounder.

factors meet the definition of confounding.

Confounding: a recap Potential confounding variables always have to be considered in the design and analysis of epidemiological studies. Confounding occurs when a confounding variable, C, is associated with the exposure, E, and also influences thedisease outcome, D.

Please do rate and liked me...........