2004 Feb;34(2):268-75..BACKGROUND: Sensitization and exposure to dust-mite antigens are causative factors in the development and exacerbation of asthma. Impermeable bedding encasements are considered a first-line treatment to reduce dust-mite antigen exposure in clinical asthma-management guidelines. Public-health recommendations for environmental asthma treatments should be based on the weight of evidence supporting the reliability of environmental interventions so that uncertainties regarding their effectiveness can be accurately communicated to patients, and so that limited public-health resources can be most effectively utilized.OBJECTIVE: To evaluate the strength of a clinical-trial evidence supporting the efficacy of bedding encasements as an asthma treatment.METHODS: A narrative review was conducted of all clinical trials involving bedding encasement for the treatment of asthma. Collective statistical analyses were also performed to characterize the quantitative effect of bedding encasement on dust-mite allergen exposure and bronchial hyper-responsiveness (BHR) when used by asthma patients.
RESULTS: Over 30 clinical trials were reviewed. Of those studies reporting adequate exposure and BHR results, four reported significant reduction in dust-mite allergen exposure and concomitant BHR reduction in active-treatment groups using bedding encasements. In 10 studies, mite-allergen exposure was reportedly decreased during the study, but BHR was not changed in the active-treatment group or was reduced to a similar degree in the active-treatment and control groups. Five other studies reported a lack of significant effect of the intervention on exposure and BHR. Collective paired analyses found that the effect of bedding encasement on allergen exposure and BHR tended toward only a modest, non-significant improvement. Collectively, effects of bedding encasement on BHR and dust-mite allergen exposure were modestly correlated only when the baseline exposure was above 2 microg Type 1 antigen per gram settled dust.CONCLUSION: Although bedding encasement might be an effective asthma treatment under some conditions, when implemented in clinical trials by asthma patients, its effectiveness is inconsistent and appears to be, at best, modest.
Therefore, its significance as a reliable asthma management modality for any individual asthma patient is uncertain. Where resource constraints are significant, targeting the use of variably effective interventions such as bedding encasements toward those patient sub-populations most likely to derive substantial benefit may gain the largest net public-health benefit.If you have trouble getting a good night's sleep on your mattress, a mattress topper might be the perfect solution. It can boost the comfort level of an old mattress for a fraction of the price of buying a new one. Sometimes called a pillow-top mattress pad, a topper is a cushion you place on top of the mattress to add softness or support. The terms "mattress topper" and "mattress pad" are often used interchangeably, but the latter also refers to a thinner type of cover that's placed over a mattress to protect it from stains. This report focuses mainly on the type of toppers used for added cushioning, but we do recommend waterproof and non-waterproof mattress pads as well.
The most common reason people decide to add toppers to their mattresses is to add new life to an older bed. Innerspring mattresses in particular tend to compress over time, losing their ability to shape themselves to a sleeper's body. A mattress topper can add an extra layer of cushioning, relieving pressure points and enhancing sleep quality. However, mattress toppers can't compensate for major problems such as sagging, sinkholes or springs poking through the mattress cover. If your mattress is that bad, you need a new one. We have recommendations for the most popular types in our separate report on mattresses. Mattress pads aren't just for old mattresses, though. People often add a mattress topper to adjust the firmness level of a newer mattress. If you buy a new mattress and determine after a short time that it's too soft or firm for your taste, adding a topper can make it softer or firmer without the hassle and expense of trading in a nearly new model (returning a new mattress often involves shipping and restocking fees, not to mention the logistics of dealing with returning a large item).
Placing a topper on just one side of the bed can also help couples who prefer different levels of mattress firmness. Memory foam is the most popular type of mattress topper, and it tends to be the most effective at improving mattress comfort. Made from polyurethane, memory foam contains millions of open, spherical cells that respond to pressure and heat. It comes in many thicknesses and densities: In general, a thicker topper will have a softer feel, while a denser foam will provide more support. However, memory foam can trap body heat, and some say that the way it cradles the body can make it difficult to move around on. Many memory foam toppers also give off an unpleasant odor when new, although a good airing usually takes care of that. Latex foam is similar to memory foam, but it's made of either natural or synthetic latex rubber. It comes in many grades of thickness and firmness like memory foam, but generally tends to be a bit firmer. It's also somewhat less likely than memory foam to trap body heat and emit an unpleasant odor, but the "new mattress smell" can still be a problem for some users.
Latex excels at providing both softness and support and it's a good choice for allergy sufferers because it's resistant to both mold and dust mites. However, latex itself can be an allergen for some people and latex toppers are among the most expensive. Featherbeds are basically cushions stuffed with feathers or down. These add softness to a mattress, but not support. While they don't retain body heat as much as foam toppers do, they tend to compress under a user's weight and must be fluffed or shaken regularly to restore their shape. Featherbed mattress toppers are usually less expensive than foam ones. If you're sensitive to feathers, fiberbed and wool mattress toppers are very similar to featherbeds, but are made from hypoallergenic materials. Mattress pads are not mattress toppers, they are just a thin pad, with corners like a fitted sheet that go over your mattress to protect it from moisture and stains. Deep-pocket mattress pads can even fit over both a mattress topper and a mattress.
Mattress pads are very affordable and there's little variation in quality. With the high cost of mattresses, we highly recommend that everyone protect their investment from spills, stains and other accidents. analyze thousands of owner reviews and break down the data to provide specific information about different mattress topper types and brands. Our research turns up three main factors to consider when shopping for a mattress topper. Since a topper's job is to improve the comfort of a mattress, we give particular importance to how well each pad cushions and supports the body, as well as such criteria as whether it retains body heat. A good mattress topper also needs to stay comfortable over time, so we examine how well each model holds up with use and whether it needs special maintenance to keep it in good shape. Based on these factors, we identify the best mattress toppers of each type and list their pros and cons. One is sure to be the perfect choice for your best night's sleep.