## 4 Discussion  
This study analyzed the data for patients grouped by age, gender, and number of outpatient visits. As shown in Table 6, the number of prior outpatient visits for most SJS patients was less than four. This number indicates that patients can develop SJS without being exposed to the suspected medications for extended periods. Table 1 shows the percentages of Taiwan's population aged under 14 (16.95%), aged 15-64 (72.62%), and aged above 65 (10.43%) in 2008. The percentages of young people and elderly people were below 20%. However, the percentage of SJS patients under the age of 14 was 32.29%, and that of SJS patients above the age of 65 was 32.11%. This shows that in Taiwan, these two age groups have a high risk of developing SJS, which is consistent with previous studies. The percentage of female SJS patients was 51.19%, which is slightly higher than that of males, and this is also consistent with other studies. However, our gender and age distributions showed that males and females of all ages can develop SJS. Therefore, physicians of all specialties, including pediatrics and geriatrics, and even obstetrics and gynecology, must be familiar with the medications they prescribe that may trigger SJS. This study also analyzed the specific associations between the diseases and the suspected medications. As shown in Table 8, the common cold, which is recorded as a respiratory system disease, was the most common disease and was found in every outpatient group. Its proportion was the highest among all groups. Moreover, the proportion of patients aged under 14 was higher than those of other age groups of respiratory system disease, probably because patients in this age group are more likely to visit clinics to seek treatment for the common cold. The medications for common chronic diseases shown in Table 8 may also cause SJS. As a result, physicians must always be alert in prescribing medications for chronic conditions, as well as for acute diseases. In Table 8, drug (T) NSAIDs can be found in all of the outpatient visit patterns; therefore, this might be the drug most commonly associated with SJS in Taiwan. Drug (U), cephalosporporin antibiotics, was prescribed only when the number of outpatient visits was less than or equal to two. This result indicates that (U) can trigger SJS after only a short exposure. For most clinical visits in Taiwan, physicians prescribe three days' worth of medicine per visit. This means (U) can trigger SJS in just six days. On the other hand, drug (H), theophylline bronchodilators, was prescribed in cases with outpatient visit numbers greater than or equal to three. This result indicates that (H) triggers SJS only after being prescribed more than twice. As a result, physicians must be alert to repeated usage of cephalosporporin and theophylline bronchodilators to prevent SJS. As shown in Table 8, some medications in the group of 1 outpatient visit are particularly worthy of attention. First, drug (D), H2-antagonist, is in disease patterns \(<\)(12)\(>\) and \(<\)(9)\(>\), but H2-antagonist is not a medicine for skin (12) or the digestive system (9). Second, drugs (H), theophylline bronchodilators, and (M), anticonvulsant agents, are in the \(<\)(9)\(>\) disease pattern, but theophylline bronchodilators and anticonvulsant agents are not medicines for treating (9) diseases of the digestive system. Third, drugs (M), anticonvulsant agents, and (J), muscle relaxants, are in the \(<\)(7)\(>\) disease pattern, but anticonvulsant agents and muscle relaxants are not prescribed for (7) diseases of the circulatory system. As mentioned in the results section, drug (T) NSAIDs, was frequently prescribed in all the sequences of different lengths. For patients with three or four outpatient visits, drug (H) was often prescribed. Therefore, when outpatient visits are frequent within a short period, physicians should pay attention not only to NSAIDs (T) but also to theophylline bronchodilators (H).