Interface Pressures of New and Worn Standard and Viscoelastic Hospital Mattresses: A Comparative Study

Hospital mattresses have been found to be used for up to 10 years in Norway. Few studies have investigated how wear and tear affects foam qualities.

This descriptive comparative study investigated interface pressures in a sample of 5 new and worn standard and viscoelastic hospital mattresses and compared their comfort and mobility ratings.

Using convenience sampling methods, 20 healthy individuals (75% female, average age 41.3 years [SD ± 12.25]) volunteered to lay supine for 10 minutes on 5 different mattresses. Mattresses had been in use for up to 7 years (since 2011). Using a bed-size pressure mapping system, interface pressures (mm Hg) were obtained after 10 minutes. Comfort and ease of turning oneself (very poor to very good) were evaluated after the pressure mapping was completed.

Differences were found between viscoelastic mattresses and standard mattresses, with mean interface pressures ranging from 30.28 to 38.37 mm Hg (P = .011), and for the mean number of cells 60 mm Hg or above (P = .025) and 80 mm Hg or above (P = .046) between the different mattresses after 10 minutes. One standard mattress from 2014 had the highest mean interface pressure (38.37 ± 7.43 mm Hg). Viscoelastic foam mattresses had the highest comfort, and standard mattresses had the highest ease of mobility scores; however, the differences were not significant. The mean interface pressures differed between participants weighing > 100 kg and those weighing < 100 kg on the standard mattress from 2011 (46.50 ± 4.83 vs. 33.86 ± 5.83; P = .012). Similarly, the values were 41.25 ± 7.70 versus 29.78 ± 5.99 on the new viscoelastic mattress (P = .040) and 42.87 ± 4.09 versus 28.05 ± 6.16 (P = .012) on the old viscoelastic mattress.

Older standard mattresses were found to be less comfortable and had higher interface pressures compared to the new standard and viscoelastic foam mattresses.