Prevalence data

A number of methods and models have been used at sites to estimate potential risks from exposure to lead. One method is the use of prevalence data for estimating PbB levels. In this case, PbB measurements can be made at a site and extrapolated to other sites with similar environmental and demographic data. Limitations of this method include site-to-site variability with respect to, among other things, children s behavioral patterns, age, and bioavailability issues. Estimation of past exposures can be problematic because of redistribution of Pb out of the blood compartment since PbB is only an indicator of recent exposure (<90 days). 

According to the estimates performed, cocaine is the most consumed drug, followed by cannabis, amphetamine, heroin, MDMA, and methamphetamine. On the contrary, official national annual prevalence data points out cannabis as the most abused illicit drug, followed by cocaine, MDMA, amphetamines, and heroin. This suggests that the drug consumption pattern in the studied areas of the Ebro River... 

Adapted from Jacobson3, Cooper and Stroehla4 thyroid disease prevalence data from HollowellS and includes clinical and subclinical disease limited to clinical disease estimates are 500 per... 

Dinse, G.E. and Lagakos, S.W. (1983). Regression analysis of tumor prevalence data. Appl. Stat. 32 236-248. 

Survey data from Colombia show that life-time prevalence of cocaine use increased over the 1992-2004 period, from 1.5 per cent in 199211 to 3.7 per cent in 2004,12 with indications that the increase took place in the late 1990s. Life-time prevalence of cocaine use among youth, aged 10-24, was more than 5 times higher in 2001 than in 1996. This increase may have been associated with the rapid expansion of coca cultivation in Colombia in the late 1990s. A comparison of annual prevalence estimates derived from these studies, with actual annual prevalence data from the new national survey, suggests that cocaine use prevalence... 

No new prevalence data is available from Germany, the fourth largest cocaine market in Europe (approximately... 

Cannabis use among 12th graders in the USA declined by 18 per cent between 1997 and 2006 and is significantly lower than three decades ago (-29%). As compared to the peak in 1979, annual prevalence data for 12th graders show a decline of 38 per cent. 

However, when it comes to heroin abuse (or drug injecting), there seems to be a general agreement that annual prevalence data derived from national household sur-... 

For other drugs, priority was given to annual prevalence data found by means of household surveys. A number of countries, however, did not report annual prevalence data, but lifetime or current use of drug consumption, or they provided annual prevalence data but for a different age group. In order to arrive at basically comparable results, it was thus necessary to extrapolate from reported current use or lifetime prevalence data to annual prevalence rates and/or to adjust results for differences in age groups. 

With a 95% probability the likely annual prevalence estimate for the country concerned falls within a range of 0.6% to l%.g Given this close relationship between life-time and annual prevalence (and an even stronger correlation between annual prevalence and monthly prevalence), extrapolations from life-time or current use data to annual prevalence data was usually given preference to other kinds of possible extrapolations. 

For a number of developing countries, the only drug related data available on the demand side was treatment demand. In such cases, the approach taken was to look for other countries in the region with a similar socioeconomic structure, which reported annual prevalence data and treatment data. As a next step, the ratio of people treated per 1000 drug users was calculated for each country. The results from different countries were... 

The number of individuals affected by reproductive disorders is difficult to assess, and few population-based data are available for either men or women. Noticeably absent are data on fecundity and fertility impairments affecting men and only limited information on male-mediated developmental outcomes exists. Population-based data for impaired female fertility are available for select endpoints from the National Surveys of Family Growth (NSFG), which are conducted periodically and most recently in 1995. Data from the NSFG show that 6.2 million women (10.2%) between the ages of 15 and 44 in the United States had impaired fertility in 1995 (Stephen 1996). This number was estimated to increase to 6.3 million women in 2000 (Stephen and Chondra 1998). Other reproductive disorders in females that impact fecundity include endometriosis and polycystic ovarian syndrome (PCOS). The prevalence of endometriosis in women of reproductive age is reported to be 10% (Houston 1984 Olive and Schwartz 1993), and no population-based prevalence data exist for PCOS. 

A problem with prevalence studies is that they may underestimate diseases having a rapid, early fatality rate. Bacterial diarrhea in infants may be detected and then kill an Infant within a week or so. Please imagine a tropical village where 10% of the persons die from this di.sease in 1 year. However, prevalence data may reveal... 

Autism prevalence data from around the world and, indeed, even within individual countries and states, are sporadic, but they indicate rising rates almost everywhere. For example, autism rates in Iceland increased from 3.8 per 10,000 in the period of 1973-83 to 8.6 per 10,000 in the period of 1984-93.111 Thirty-one cases of autism per 10,000 births were reported in Sweden in the 1990s I12l an autism rate of 11.3 per 10,000 births was reported for people native to southern Japan 13 and rates of 30 per 10,000 in U.S. metropolitan areas was reported in 2003J14 ... 

There have been a number of Unilever-sponsored 3-year caries clinical trials during which calculus prevalence was also recorded. Table 1 summarises the variations in the scoring system employed. For the purpose of the present analysis, scores have been combined to produce two subject groups those with calculus and those without calculus. Mean baseline caries and calculus prevalence data from six trials are listed in table 2, whilst corresponding 3-year caries increment data and calculus prevalence at the end of each trial are listed in table 3. 

A comparison of the caries prevalence data of table 2 and the corresponding caries increment data of table 3b shows that the percentage difference in... 

Incidence estimates of CKD have generally been extrapolated from the USRDS. The fonr most common medical conditions associated with incident Stage 5 CKD are diabetes meUitns, hypertension, glomerulonephritis, and polycystic kidney disease. The respective incidence rates for these conditions are 150 cases/million, 80 cases/ million, 22 cases/million, and 5 cases/milhon. Mnch like the prevalence data, the estimates of incident Stage 5 cases are also greatly increased in the presence of advanced age and black race. For example, the rate of Stage 5 CKD is fonrfold higher for African-Americans as compared to Cancasians. ... 

Based on prevalence data from the National Centers for Health Statistics, an estimated 15.8 million adults, or 12% of those between 25 and 74 years of age, have signs and symptoms of OA. The prevalence of OA increases with age. In those under age 45, about one-fifth have OA of the hands, while for those aged 75 to 79 years, 85% have OA of the hands. OA of the knee occurs in less than 0.1% of those aged 25 to 34 years, but in 10% to 20% of those aged 65 to 74 years. 

Prevalence data varies because screening uses a simple Hgb test, arbitrary normals are used, and selection of samples in population surveys tends to lead to errors. The normal ranges for Hgb and Hct are so wide that a patient may lose up to 15% of their RBC mass and still have a Hct within the normal range. 

Detailed information concerning the extent of the problem in analgesic nephropathy is limited, particularly for recent years. National annual data are collected in Austraha/New Zealand by the Austrahan and New Zealand Dialysis and Transplant Registry (ANZDATA) [51] and in the United States by the United States Renal Data System (USRDS) [52]. In Europe, the registration system of the European Dialysis and Transplant Association (EDTA) [53] pubUshed regularly incidence and prevalence data of analgesic nephropathy for all European countries in the past. 

The most comprehensive prevalence data for the United States come from the National Health and Nutrition Examination Survey (NHANES), a now-continual series of cross-sectional studies of the American population, which seek to assess the health status of both adults and children throughout the nation. NHANES III, which was conducted from 1988 to 1994, is the most recent complete data set to be analyzed. Certain population groups,... 

Biirgi, H., Supersaxo, Z. Selz, B.(1990). Iodine Deficiency Diseases In Switzerland One Hundred Years After Theodor Kocher s Survey A Historical Review With Some New Goitre Prevalence Data. Acta Endocrinol (Copenh), Vol.123, No.6, pp 577-590, ISSN 0001-5598... 

The simplest way to assess the association between risk factors and WRMDs is to ctilculate odds ratios (Table 29). To do this, the prevalence data obteiined in health surveillance tire linked with the data obtained in risk-factor surveillance. The data used can be those obtained with symptom ques-... 

Another source of United States epidemiological data is provided by the National Center for Health Statistics headquartered in Hyattsville, MD. They collect prevalence data on a large number of acute and chronic conditions based both on surveys and interviews. NCHS will not have data on effects of particular chemicals, but data on the prevalence of certain conditions may be useful in trying to relate exposure to effects. NCHS also collects morbidity and mortality data for the entire United States and publishes monthly and annual statistics. 

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