Efficacy of Lodotra®(Prednisone) in Reduction of Morning Stiffness Duration(K-IMPROvE)

Inclusion Criteria: * Patients who are diagnosed more than 3 months * Morning stiffness on previous treatment with or without oral steroids (below or equal to 10mg per day, methylprednisolone doses were converted into prednisone doses as follows: prednisone dosed=methylprednisolone dose\*1.25), average daily duration of 45 min or more. * Average daily maximum pain intensity score (100 mm VAS) of 30mm or more. * DAS-ESR ≥3.2 * On DMARD treatment including MTX for ≥3months and stable treatment dose within the past 30 days. There are no limitations on number of DMARDs treatment.(Except patients who have experience of adverse drug reaction of MTX or difficulty to administer MTX due to disease specific condition.) * Able to perform study procedures and given written informed consent. * Naïve patients with Prednisone MR(Lodotra® ) or patients not treat with Prednisone MR(Lodotra®) within 4 weeks(28days) * Subject who keeps to administer study drug at 22±30 daily * Subject who provide signed and dated written voluntary informed consent Exclusion Criteria: * Patients who suffers from another disease, which requires glucocorticoid treatment during the study period. * Synovectomy within 4 months prior to study start. * Patients who underwent joint injections on only fingers and wrists(both sides) within 4 weeks prior to first visit. Clinically significant disease which, in the investigator's opinion, would exclude the subject from the study. * Significant renal impairment (serum creatinine\>2.0mg/dl) * Significant hepatic impairment (\>3 times the upper limit of normal range in each site) * All contra-indications for glucocorticoids.(established new osteoporotic fractures history of corticoid psychosis, herpes simplex and herpes zoster, varicella infection) * Uncontrolled DM(HbA1c\>8.0) * Women of child-bearing potential, defined as all women physiologically capable of becoming pregnant. UNLESS they are: * women whose career, lifestyle, or sexual orientation precludes intercourse with a male partner * women whose partners have been sterilized by vasectomy or other means * two birth control methods. The two methods can be a double barrier method or a barrier method plus a hormonal method. Adequate barrier methods of contraception include: diaphragm, condom (by the partner), intrauterine device (copper or hormonal), sponge or spermicide. Hormonal contraceptives include any marketed contraceptive agent that includes an estrogen and/or a progestational agent. * Pregnant or nursing (lactating) women, where pregnancy is defined as the state of a female after conception and until the termination of gestation, confirmed by a positive urine pregnancy test * Participation in another clinical study within the past 30 days * Known hypersensitivity to prednisone * Infection patients without effective antimicrobial and systemic mycosis infection patients(infection might be aggravated due to suppression of immunologic function.) * Patients with immunization with live vaccines within 2 weeks of enrollment or planned during the study * Since this drug contains glucose, patients with rare hereditary problems of galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption should not take this drug.