جستجوی مقالات مرتبط با کلیدواژه « positive predictive value » در نشریات گروه « پزشکی »

The status of the axillary lymph node is the most important factor in determining the prognosis of breast cancer. The aim of this study was to evaluate the sensitivity and specificity of Axillary Ultrasound (AUS) in the diagnosis of lymph node involvement in breast cancer patients referred to the Breast Cancer Research Center (BCRC) between March 2015 and Aug 2016.
Through a cross sectional study, all patients with a diagnosis of non-metastatic breast cancer with Stage I, II, IIIA and no chemotherapy before surgery were evaluated. The results of AUS and pathology after surgery were collected and analyzed using SPSS based on sensitivity and specificity formula.
Of a total of 140 patients, the average age was 48.87 and the mean size of masses was 2.31 cm (0.4 -10 cm). Physical examination was positive in %14.6 of patients, positive AUS in %28.6 and pathologic axillary involvement in %39.2 of the patients. Sensitivity, specificity, PPV and NPV of AUS in diagnosing lymph node involvement were %55.5, %88.3, %75 and %76 respectively. Sensitivity, specificity, PPV and NPV of clinical examination were %31.48, %97.67, %89.4 and 69.4. The combination of positive AUS and physical examination were along with pathologic axillary involvement in %92.3 of patients. False positivity and false negativity of AUS were %11.6 and %17.1 in all.
The sensitivity and specificity of AUS in our patients is the same as the results of other countries. Clinical examination alone has a high false negative and low sensitivity, however AUS in addition to physical examination has higher sensitivity which could predict axillary involvement and lead to axillary dissection without sentinel node biopsy. Negative AUS has about %24 false negativity and SLNB could not be omitted until the results of trials would be published.

Appendicitis is considered as one of the major causes leading to acute abdomen and as one of the most prevalent cases in urgent need of surgery. Although diagnosis of acute appendicitis is based on the accounts¡ clinical examinations and laboratory results¡ but making any certain diagnosis often seems to be quite difficult¡ even for experienced surgeons. This problem is more appreciable/ discernible concerning some groups like pregnant women¡ children/infants¡ and aged people. So¡ there has been always a constant effort to achieve inexpensive and feasible/available methods for improving the process of diagnosis.
All the patients who were suspected of having acute appendix¡ operated in the emergency of Be''sat Hospital in Hamadan during six months ago¡ have been checked. 5 cc peripheral blood has been obtained from each of those hospitalized patients whom were suspected of having acute appendicitis and supposed to have surgery afterwards. Serum DLactae level measured using Spectrophotometric method. Serum level of above 0.25 mg in deciliter has been considered for patients whom their testresult was positive.
Findings: In acute appendicitis diagnosis¡ the sensitivity of D-Lactae measurement was (79%) and specificity (58%) for all patients¡ positive predictive value (87%) and negative predictive value (43%) as the result of the test have been calculated. The accuracy of the test was 74%.
Discussion & Serum lactate test could be an influential aid in diagnosis of acute appendicitis. This test is quite inexpensive and widely available. Besides¡ the method of measurement is simple. Test sensitivity¡ in all age groups¡ is high; positive predictive value of the test¡ in comparison with other laboratory tests¡ is high. Accuracy of the test is also high and is comparable to other laboratory tests.

Rubella vaccination is essential due to the relationship between the primary infection and congenital abnormalities. Detection of IgM is the most common method of diagnosing acute rubella infection. In Iran, no rubella outbreak has been reported after the global vaccination; although positive rubella IgM cases have been detected. Approaching elimination of a viral infection, its incidence rate and the positive predictive value (PPV) of the diagnostic test would be reduced. Recently, adequate vaccination coverage leads to a reduction in rubella incidence, in such a situation this study estimated the PPV of rubella specific IgM. Serum samples from cases with fever and rash, during three tandem years were collected from all over the country. To evaluate the PPV of IgM detection in acute rubella infection diagnosis, all the sera were subjected to IgM detection, then all IgM positive cases were evaluated via IgG avidity assay. The PPV of IgM detection test to detect acute rubella infection was 15.8%. In conclusion, giving the appropriate immunization coverage in the country, the PPV of detecting rubella IgM was low. Therefore, diagnosis of acute rubella infection should not be confirmed only based on IgM positive result.

Endometrial cavity is frequently studied because of abnormal uterine bleeding، pelvic pain، infertility، pregnancy complications، and suspect cases of endometrial cancer. Abnormal uterine bleeding dedicates one third of women''s referral to gynecologic specialists. Transvaginal Ultrasonography is one of the diagnostic modalities of endometrial examination. The aim of this study is to compare the endometrial transvaginal ultrasonography with histopathology as a golden standard in patients complaining abnormal uterine bleeding. This descriptive-analytical retrospective study was held on of 225 patients complaining abnormal uterine-bleeding who had transvaginal ultrasonography and definite histopathological reports admitted in Shahid Sadooghi، Goodarz، and Mojibian hospitals of Yazd، Iran in the years 2006-2007. Transvaginal ultrasonography and histopathology results of the questionnaire were recorded separately. Then، the sensitivity، specificity، positive predictive value، and negative predictive value of transvaginal ultrasonography technique for diagnosis of abnormal endometrium، retained product of conception، subendometrial leiomyoma، endometrial hyperplasia، endometrial polyp، and endometrial cancer were calculated by SPSS software version 11. P value less than 0. 05 was considered statistically significant. The sensitivity، specificity، positive predictive value، and negative predictive value of transvaginal ultrasonography are 100%، 29. 6%، 81. 8%، 100% in diagnosing abnormal endometrium، 100%، 86. 7%، 51% and 100% in diagnosing retained product of conception، 100%، 87. 5%، 58. 6%، and 100% in diagnosing subendometrial leiomyoma، 89%، 100%، 100%، and 96. 6% in diagnosing endometrial hyperplasia، 44. 5%، 100%، 100%، and 90. 4% in diagnosing endometrial polyp، and 33. 3%، 99. 5%، 50%، and 99. 1% in diagnosing endometrial cancer respectively. Transvaginal ultrasonography has enough sensitivity for diagnosis of abnormal endometrium، subendometrial leiomyoma، and retained product of conception، and also has enough specificity for rejecting endometrial polyp، endometrial hyperplasia، and endometrial cancer.

Considering the high application of diagnostic tests in medical practice، understanding the concept of diagnostic test evaluation indices is highly important. Ability of test in distinguishing healthy subjects from patients is evaluated by sensitivity، specificity، positive predictive value (PPV)، negative predictive value (NPV). Although their understanding is relatively straightforward، they are often used mistakenly or interchangeably. We have tried to present these concepts utilizing the diagrams to make it easier to understand and remember. we used diagrams to illustrate the concept of diagnostic indexes. Then we showed the effect of change of prevalence of disease in these indexes. Sensitivity and specificity are not sensitive to the prevalence of disease in the population. On the other hand positive predicted value increase when the prevalence of disease increase and negative predictive value increase when the prevalence of disease decreases. Although it has been shown that sensitivity and specificity are essential in evaluation of accuracy in diagnostic tests، their ability to discover the degree of confidence is limited، so the predictive values is used to indicate the posterior probability of disease after observing the test results. It should be considered that predictive values are dependent upon the prevalence of disease in population and should not be generalized for different populations with different prevalence of diseases.

To determine the relationship between cervical length at 16 and 24 weeks of gestation and the occurrence of preterm labor.

A prospective cohort study was performed on 153 pregnant women in two groups (75 and 78 person) after measuring cervical length with vaginal sonography. We calculated the incidence preterm labor m both groups, plus the sensitivity, specificity, positive and negative predictive values for cervical length.

The incidence of preterm labor was 17.3% ( 13/75) in the group with cervix length of less than 35 mm and 6/4% (5/78) in the group with cervical length ;::JS mm. The relative Risk was 2.7 (95% CI=l.3-4.5). Sensitivity, specificity, positive and negative predictive value of cervical length on preterm delivery with a cut-off point of 35 mm were 72%, 54%, 17% and 93% respectively. In the multivariate analysis of job, education, parity, gravidity and cervical length only cervical length was significantly related to preterm delivery (P<0.01). The cervical length also had a significant correlation with preterm delivery (P<0.001, r =0.61).

Cervical length between 16 and 24 weeks of gestation is a strong-predictor of preterm labor.