A cross-sectional study was conducted to explore the betel-chewing behavior of junior high school students in Taichung County in 1998. The sample consisted of 2244 students in the general area and 84 students in the aboriginal area. Fifty percent of the students in the aboriginal area had had the experience of chewing betel, and this figure includes 30.1% of the habitual chewers. The prevalence of habitual betel chewers among the students in the general area is 4.3% to 5.0%. The major source of betel quid is friends or classmates, and curiosity accounts for most students' first experience of betel chewing. Sixty percent of the students started betel chewing in elementary school. An effective health education program for students in the aboriginal area and younger students in the general areas as well as an evaluation procedure for the effectiveness of the program are needed to prevent the increase of betel chewing among Taiwan's youth.

A cross-sectional study with stratification sampling was conducted to explore the parental influence of betel-chewing behavior among junior high school students in Taichung County in 1998. The sample consisted of 2244 students in three different districts in Taichung County: the mountain line area, the seashore area; and the satellite cities area (near Taichung City). A self-reported questionnaire was filled out anonymously by the sampled students. Fifty percent of the students' fathers and 2.5% of the students' mothers are betel chewers. A higher prevalence of betel chewing is found among students whose parents are betel chewers. Also the lower the father's educational level, the higher the prevalence of betel chewing among the students. Compared with students whose fathers have more than 12 years of education, the odds ratio is 2.35 for the prevalence of betel chewing among students with fathers whose educational levels are no more than 9 years. However, parents' vocations are not related to the prevalence of betel chewing among junior high school students. Finally, students whose parents are separated or divorced have a higher prevalence of betel chewing. An effective health education program for the high-risk group students and an evaluation procedure for the effectiveness of the program is necessary to prevent the increase of betel chewing among Taiwan's youth.

The aim of this study was to evaluate the association between postmenopausal osteoporosis and kidney-vacuity syndrome. Eighty-one postmenopausal women were enrolled; their age were between 40 to 65 years old. The mean ages of the non-osteoporosis group and osteoporosis group were 54.0 +/- 4.8 and 58.9 +/- 5.9 years old, respectively. Bone density examination was performed by DEXA technique and the diagnosis of osteoporosis was made by finding 2.5 standard deviations below the bone density of healthy youths. Kidney-vacuity syndrome was deduced according to the diagnostic criteria developed in the National Congress on Chinese Medicine and Sino-Western Combined Geriatric Medicine held in the People's Republic of China in 1986. The results showed that patients with kidney-qi-vacuity and kidney-yin-vacuity were more likely to have osteoporosis than those who were not. No significant difference in the rates of osteoporosis between the kidney-yang-vacuity group and non-kidney-yang-vacuity group was found. The kidney-qi-yin-vacuity group had a higher probability of developing osteoporosis than the kidney-qi-vacuity or kidney-yin-vacuity group. By logistic regression analysis, patients with kidney-qi-vacuity or kidney-yin-vacuity were more likely to develop osteoporosis than those who were not. In conclusion, a marked association between kidney-vacuity syndrome and postmenopausal osteoporosis was observed. Patients with kidney-qi-yin-vacuity syndrome were more likely to get osteoporosis than those with kidney-qi-vacuity syndrome or kidney-yin-vacuity syndrome.

Various sociocultural factors affect healthcare-seeking behaviors. In Taiwanese society, superstitions and lunar festivals play important roles in people’s lives. We investigated the impact of “Ghost Month” (the 7th lunar month) and Chinese New Year (the 12th lunar month and the 1st lunar month of the following year) on the number of elective surgeries and emergent surgeries in Taiwan. The number of total knee replacement (TKR) surgeries and proximal femur fracture (PFF) surgeries in each lunar month from 2000 to 2011 were extracted from the Taiwan National Health Insurance Database, a computerized and population-based database. Patients were then sorted by location of residence or gender. The average number of TKR surgeries performed was significantly lower during the 1st, 7th, and 12th lunar months in urban areas, whereas in rural areas this trend was only evident in the 7th and 12th lunar months. There was however, no significant difference in the average number of PFF surgeries in each lunar month except for an increase seen in the 1st lunar month in rural patients (p<0.05). When sorted by gender, the average number of TKR surgeries was significantly decreased in the 7th and 12th lunar months in male patients, and decreased in the 1st, 7th, and 12th lunar months in female patients. In contrast, there was no difference in the average numbers of PFF surgeries in the 7th and 12th lunar months either in male or female patients. We proposed that the timing of elective surgeries such as TKR might be influenced by Ghost Month and Chinese New Year; however, emergent PFF surgeries were not significantly influenced by sociocultural beliefs and taboos in Taiwan.

We consider the estimation problem of a proportional odds model with missing covariates. Based on the validation and nonvalidation data sets, we propose a joint conditional method that is an extension of Wang et al. (2002, Statistica Sinica 12, 555-574). The proposed method is semiparametric since it requires neither an additional model for the missingness mechanism, nor the specification of the conditional distribution of missing covariates given observed variables. Under the assumption that the observed covariates and the surrogate variable are categorical, we derived the large sample property. The simulation studies show that in various situations, the joint conditional method is more efficient than the conditional estimation method and weighted method. We also use a real data set that came from a survey of cable TV satisfaction to illustrate the approaches.