Underreporting

Limited Knowledge of Exposure and Reporting Rates in Postmarketing Data. Unlike clinical trials and electronic medical records in clinical practice, postmarketing voluntarily reported data contain limited information about the total number of patients exposed and the duration of exposure. This problem is compounded by the fact that adverse events are often underreported [2,9]. 

Viral hepatitis can occur at any age and is the most common cause of liver disease in the world. The true prevalence and incidence may be underreported because most patients are asymptomatic. The epidemiology, etiology, and pathogenesis vary depending on the type of hepatitis and will be considered separately below. 

Urinary incontinence (UI) is defined as the complaint of involuntary leakage of urine.1 It is often associated with other bothersome lower urinary tract symptoms such as urgency, increased daytime frequency, and nocturia. Despite its prevalence across the lifespan and in both sexes, it remains an underdetected and underreported health problem that can have significant negative consequences for the individual s quality of life. Patients with UI may be depressed due to a... 

Working conditions were studied in one of the collective farms in Tajikistan where vamidothion was used to fight spider mites in cotton [A52]. The vamidothion concentration in work zone air when it was sprayed from airplanes and tractors reached 0.9 mg/m3, according to underreported data (the public health standard was 0.1 mg/m3) ]. In 1978, vamidothion was banned however, the 1997 Official Handbook of the Health and Epidemiological Service of Russia [10] still lists this pesticide, with no mention of the ban ... 

Therefore Table 3.9, constructed from Soviet data on DDT and HCH, although it includes more detailed observations, does not allow us to come to a final conclusion. It seems that the results were clearly underreported. 

In the first few years, there was a known underreporting, bur reliable cancer incidence data from 1955 and up to date are available (Cancer Registry, 1978). 

Martin, R.M., Kapoor, K.V, Wilton, L.V and Mann, R.O. (1998). Underreporting of suspected adverse drug reactions to newly marketed ( black triangle ) drugs in general practice Observational study. Br. J. Med. 317 119-120. 

We suspect that the magnitude of most of the associations noted between meat or coffee and specific fatal diseases are somewhat underestimated because Adventists may tend to underreport the amount of meat or coffee they use. If a substantial number of subjects actually use more meat and coffee than they reported on the Initial questionnaire, it would tend to make it harder to find the real associations, and the observed associations would tend to be weaker. Furthermore, we may have missed associations because subjects changed their habits during the 21-year follow-up period. All observed associations are based on meat and coffee use at the time subjects completed the baseline questionnaire (1960). Subsequent changes in these habits would tend to reduce or eliminate the possibility of finding disease associations with these habits. Failure to find associations, or detection of weak associations, could also result from the fact that our study population contains relatively few subjects who are very heavy users of meat or coffee, while it contains an abundance of subjects who have no exposure to these items. 

Alcohol consumption is very difficult to assess. There is widespread belief that individuals underreport their intake and there are no reliable laboratory tests available for definitive diagnosis of alcohol abuse. A combination of abnormalities in the plasma activity of gamma-glutamyl transferase (GGT or yGT), AST and reduction in erythrocyte mean cell volume (MCV) maybe useful and all are routine lab. tests. A potential marker of interest is carbohydrate-deficient transferrin (CDT) which is an abnormal isoform of serum transferrin arising due to defects in the attachment of carbohydrate chains to the protein core. Unfortunately, CDT is a somewhat specialized test, not performed by most laboratories. Other markers which have attracted some research interest are ethyl sulphate and ethyl glucuronide. Excretion in the urine of these metabolites occurs for up to 50 hours after binge drinking so they offer a useful index of recent heavy alcohol intake. 

SEs are produced during the late log or stationary phase, and SE production is strain-dependent. SEB and SEC are produced in great quantities. Toxins such as SED occur in small amounts (Su and Wong, 1993), and so cases of poisoning are underreported due to the mild symptoms of intoxication they produce. 

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