Abstract & Commentary
Synopsis: When administering the MMSE, use of serial 7s produces a more reliable score.
Source: Espino DV, et al. J Am Geriatr Soc. 2004;52: 822-827.
The San Antonio Longitudinal Study of Aging (SALSA) enrolled Mexican-American (MA) and European-American (EA) elders from 3 distinct neighborhoods that were predominantly low-, middle-, and upper-income. The neighborhoods had varying mixes of MA and EA with the low-income one being almost exclusively MA, the middle-income one an even split, and the upper-income one 90% EA. All subjects were given the Mini-Mental State Examination (MMSE) with 2 modifications: all were asked to spell "WORLD" backwards and in performing the 3-step command ("Take this paper in your right hand, fold it in half, and place it on the floor."), they were instructed to place the paper on their lap. The MMSE was scored 3 different ways: taking the better score of serial 7s or backwards spelling, serial 7s alone, and backwards spelling alone.
The subjects fell into 3 groups: EA, MA who were interviewed in English (MAE), and MA who were interviewed in Spanish (MAS). There were 807 subjects (363 EA, 320 MAE, and 124 MAS), averaging 69 years in age and predominantly female (58%). The 3 groups differed in educational achievement with EA having completed high school and some college, MAE having completed some high school, and MAS having completed some grade school. Most (80%) of the MAS lived in the low-income neighborhood; only 47% of MAE lived there. EA rated their health better than MA. This was borne out when comparing the incidence of diabetes mellitus, type 2: 12% EA, 30% MAE, and 50% MAS.
The scores on the MMSE by ethnic group and method of scoring were as follows:
The coefficients of variation (a measure of heterogeneity) were lowest for EA and highest for MAS with MAE in the middle. The serial 7s only scores had greater variability than spelling or serial 7s and spelling only. The serial 7s only scores also had the highest alpha coefficients, a desirable trait for screening tests.
Comment by Allan J. Wilke, MD
The MMSE celebrates its 30th birthday next year. As Dr. Marshall Folstein has noted, "age and education produce remarkably similar results across cultures." In the same article he notes that there is ambiguity in scoring serial 7s and that serial 7s and spelling "world" backwards are not comparable. His personal practice is to use spelling only if "the patient absolutely refuses to try" serial 7s.
Dr. Wilke, Assistant Professor of Family Medicine, Medical College of Ohio, Toledo, OH, is Associate Editor of Internal Medicine Alert.