Introduction: Hepatitis B is one of the most common reasons for chronic hepatic dise-ases around the world, so that nowadays two billion people carry this virus and about 350 million people are suffering from chronic hepatitis B infection. As there are different and effective factors that are important in affection and progression of hepatitis B, the aim of this study is the evaluation of epidemiologic factors that are related to outcomes of treatment in patients with chronic hepatitis B in Birjand.

  Materials & Methods: This descriptive-ana-lytic study was done on 301 patients with chronic hepatitis B referring to Vali Asr hospital´s infectious diseases clinic during 1375-1390 in Birjand. All patients had a document containing demographic inf-ormation, virus transmission way, risk fac-tors and the way for awareness about dis-ease. Then some tests were done included: Aspartat amino transferase (AST), alanin amino transferase (ALT) , hepatitis B capsulate antigene (HBe Ag) , hepatit B external antigene (HBs Ag) , their conclusions and serial sonography were recorded in documents. Patients older than 13 years with complete information in their documents were entered the study after expressing the consent.

  The data were collected regarding to the present check list, then they were analyzed 

  by statistical descriptive and inferential tests in p < 0.05 level.

    Finding: The mean age for 301 patients was 32.9±10.5. There was no statistically significant relation between treatment outcomes and sex, average of AST, PT, α-fetoprotein, job and risk factors. There was significant relation between treatment outcomes and age, average of ALT, HBV DNA, HBeAb, HBeAg, type of treatment and sonography. The highest treatment

  efficacy was with Interferon 28/6% that reached to 50% with a 5-year fallow up (P < 0.001). At first, combined therapy with lamivudine and interferon leaded to 12.5% complete recovery that at last reached to 14.3% (P=0.0001).

    Discussion & Conclusion: The progression of disease was accompanied by the age older than 50 years, negative HBeAb, positive HBeAg, positive HBVDNA, high ALT level, positive HBvDNA and ab-normal sonography. Treatment with int-erferon was more effective than other anti-viral drugs, but the combined therapy was more effective than mono therapy because of disease relapse in 5-year follow up.