ABSTRACT
PURPOSE: To determine the sensitivity and specificity of vision screening in Iranian schools where teachers have provided screening services for over 10 years. METHODS: In a cross-sectional study, using random cluster sampling, 1163 school children were selected from 14 clusters. Data of vision tests performed by teachers were derived from 847 student records and compared with data obtained by optometrists. Measurement of the uncorrected visual acuity was done using the E chart by both the teachers and the optometrists. Examinations performed by optometrists were regarded as gold standard in this study and the sensitivity and specificity of the examinations performed by teachers were evaluated against them. Uncorrected visual acuity worse than 20/25 in the better eye was considered as the cut-off point for students' visual impairment. RESULTS: The sensitivity and specificity of the screening tests performed by the teachers were 37.5% and 92.0%, respectively. The positive and negative predictive values were 25.0% and 95.4%, respectively. There was no significant difference in the validity of the vision test between males and females (P = 0.093 for sensitivity and P = 0.052 for specificity). CONCLUSION: Our findings showed that teachers missed a significant number of children with vision impairment and the examinations performed by teachers lacked the required sensitivity for case detection. The number of false negative results should be minimized through continued investment in accurate screening processes.
Subject(s)
Faculty , Optometry , Refractive Errors/diagnosis , Vision Disorders/diagnosis , Vision Screening/methods , Adolescent , Child , Cross-Sectional Studies , False Positive Reactions , Female , Humans , Iran/epidemiology , Male , Predictive Value of Tests , Refractive Errors/epidemiology , Reproducibility of Results , Sensitivity and Specificity , Vision Disorders/epidemiology , Visual Acuity/physiologyABSTRACT
INTRODUCTION: As one of the most common cancers among head and neck malignancies, cancer of the oral cavity probably has some variations in countries with a high prevalence of esophageal cancer. MATERIALS AND METHODS: Patients with oral cavity cancer who were treated at two tertiary referral centers from January 1999 to January 2009 were included in this study. In addition to demographic data, information regarding personal and family history of head and neck cancer, use of dentures, presence of immune deficiency, consumption of alcohol, and incidence of cigarette smoking was collected. Additionally, a history of opium usage was obtained from the participants in this study. Moreover, an appropriately matched control group was selected for comparisons between the risk factors. RESULTS: A total of 557 patients were entered into this study over a 10-year period, of whom 219 (39.3%) were female and the remaining 338 (60.7%) were male. The tongue was the most common site of cancer and 9% of the patients had a history of opium abuse, but more than half of the patients did not have any recognized risk factors. The incidence and stage of cancer had a significant relationship with cigarette smoking (P= 0.013). CONCLUSION: Tongue cancer in non-smokers is the predominant pattern of oral cavity cancer in Iran.
