Relative risk , spontaneous rate

In these types of epidemiological studies, a relative risk is often calculated which compares the risk of getting a disease with the drug (in this case a birth defect) against the spontaneous rate seen in the population not taking the drug. 

Spontaneous reports received by the Netherlands Pharmacovigilance Foundation between 1985 and 1999 have been analysed in a case-control study (15). Relative to other antidepressants, SSRIs were about twice as likely to be implicated in spontaneous reports of extrapyramidal reactions (OR = 2.2 95% Cl = 1.2, 3.9). The risk was greater in patients who were also taking neuroleptic drugs. This result suggests that SSRIs have a modestly increased risk of producing extrapyramidal reactions compared with other antidepressants. However, increased reporting can be influenced by increased awareness. In addition, no account was apparently taken in this study of relative prescription rates of different antidepressants. 

These results suggest that the risk of mania or hypomania in the long-term treatment of recurrent unipolar depressed patients is relatively small. The 12 placebo-controlled studies of acute treatment in less carefully defined samples support higher incidence rates (around 6-7% for hypomania and 1-2% for mania), but these figures may be inflated owing to the inclusion of bipolar patients with a high risk of a spontaneous switch (94). 

Human exposures to RF radiation arise from military use, industrial use, broadcasting, and cellular phone use. These exposures have been linked to increased numbers of spontaneous abortion, neurological effects, altered red and white blood cell counts, increased somatic mutation rates in lymphocytes, cardiovascular effects, increased cancer risk, and increased childhood cancers/28 311 Other studies.however, have refuted these findings) 27,32 As stated in the introduction, only a relatively few studies addressed the combined effects of toxic chemical and RF exposure. A thorough search of the literature shows that such studies have not been refuted. The following are illustrative examples of these mixture studies. 

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