Inaccuracy of the Dinamap 8100 portable monitor

Abstract

Prevalence of haemochromatosis among 11 065 presumably healthy blood donors. N Engl J Med 1988; 318: 1355‐62. in genetic haemochromatosis, ten (9·1%) were heterozygous for the mutation, and 100 (89·9%) had normal alleles. Among the 82 controls, none were homozygotes, four (5%) were heterozygotes, and 78 (95%) had normal alleles. The results from controls are not statistically significantly different from those with alcoholic liver disease (p=0·267). The 9% prevalence of heterozygosity in the chronic alcoholic liver disease group is comparable with that predicted in healthy blood donors with less sensitive techniques. In this latter group the prevalence of homozygosity was 0·5% with an estimated heterozygosity of 10%. 5 The heterozygosity found in our study is also similar to the prevalence (11%) in 101 healthy blood donors tested for the mutation with a restriction enzyme digest technique similar to ours. 2 The low prevalence (4·9%) of the mutation in the control group of chronic cholestatic liver disease suggests that it is not an adverse factor in disease progression in the vast majority of such cases. Now that a fairly simple test is available, larger population-based studies can be done to find true prevalence of the mutation. The relatively low prevalence of heterozygosity for the mutation in the candidate gene for haemochromatosis suggests that this is not a major risk factor in the development of chronic alcoholic liver disease, nor in chronic cholestatic liver disease.