Bad experience as first time patient I arrived at 3:27 for my 3:30 appt. I was told that I'd be called in as soon as I returned the paperwork. After returning the paperwork I waited at least 30 minutes and was then called back to the front desk. At that point I was told I had to reschedule and come another time. Dr. Sievers wouldn't see me because I was supposed to arrive 20 min. early to fill out the forms. I hadn't been told this when I made the appt. The day before the appt they left a voicemail saying 'Please arrive at 3:05'. They did not say 'You must arrive at 3:05 or your appt may be forfeited'. The front office person and physician's asst were sympathetic but couldn't do anything about it because it was Dr. Siever's decision. I've never before had an experience like this of a dr being so rigid and inflexible, making me leave because I was a few minutes late, and not even clearly communicating her policy so I would know. I'm not going back. I don't want to see a dr like that. I'll find someone else. read more

I would never recommend Dr. Tammy Cheng (sievers) she was my sisters doctor for years. She is very condescending in her remarks regarding other doctors who are specialist in there field of treatment. She thinks nothing of sticking her nose into the medication that other doctors have prescribed and telling the patient to not take it or the treatment the specialist prescribed. She needs to mind her own business in her field of medication and treatment of RA. She can be rude and condescending to the patient. I am sohapot to know there are other RA DOCTORS in Ventura County. I am so glad to have been able to find a great 5 star rated RA in Ventura County. Go to all the other web sites and see h e reviews under Tammy Cheng and her married name now Tammy Sievers. read more

If I were reviewing 2 years ago she would have gotten 5 stars, compassionate and seemed generally worried about my well being. My last visit with her she was going to put me on a very important medication after I gave birth, she told me to see her 2-4 wks post partum to get going on a new med. When that time came I couldn't get an appt for almost 3 wks so I tried contacting her seeing if she could just write the rx but only her nurse called back saying she refuses bc she's never prescribed that before. Even though she told me to go on the med!!!! It was a life saving blood thinner to prevent stroke and she refused. Her staff was very rude when I asked for a copy of my files and rolled there eyes at me. I had to go see my GP just to get the rx that I knew I needed. I am now seeing a new rheumy who I can get an appt with easily and actually follows through with what they say. read more

Dr Cheng is a horrible doctor that gave me the worst experience of my life. .It was so sad. I cried. I am so emotioanl about the pain im in and have been diagnosed by a primary physician with firbomyalgia. She did not behave with care and treated me like I had nothing wrong. I left in tears and told the staff how awful it was. I had waited for the oppointment for months. and got childcare for my daughter/. I was so excited to finally see a specialist to help me with my problems. She was so rude I even heard her right outside the door saying "why they send me the wrong patients". I get shooken up just talking about the experience. This woman should not even have her license. She spent less than 5 minutes asking me questions, and only regarding sleep. All research shows this is not even accurate questions for fibromyalgia. then she poked me once or twice in the leg and that was it "nothing wrong with me" sorry "she said. I also did not like the lady that worked with her and took my blood pressure. She was cold and I dont even think she actually counted my breaths. worst experience of my life. Horrible doctor. judjemental, bad english and just a bad person. gossips and no etiquette or bed side manner whatsoever. read more

Update: RUN AWAY!!! I wanted to update my review from 3/13/14 as my experience changed completely. Dr. Cheng initially was wonderful and seemed very eager to help, although her reviews were not good. My insurance referred me to her and so I went in and left pleased. I arrived at her office in possession of my past medial records and diagnosis over ten years old (confirmed by three rheumatologists), she reviewed them and agreed to follow the treatment plan that I was using, as it was working well for me. My next few visits were good, Dr. Cheng was nice and still seemed on board. Then things CHANGED...on my 4th visit I hardly recognized her. She acted as if she never met me, questioned my diagnosis and said she thought I needed to be retested. She stopped my treatment plan and order more testing. Refused to refill my prescriptions, filled by her for the past four months. I tried to feel her out and see if it was just a bad day, or were the other reviews about her really right?? When I questioned her reasoning for retesting she got angry and said that I did not show enough symptoms of this disease. Duh, of course I wasn't showing all of the symptoms, that is what the medication was for -- to ease them. I let her know that I was not going to pay for tests that have already been done numerous times in the past and all had the SAME results. She then stepped out of the examination room and sent a nurse in with a print out of blood-work and tests to be done. I left in awe of the appointment and called my insurance to see if I could be referred somewhere else. They said it could be a three month process. Feeling a bit desperate, I called her office and spoke with her nurse. I explained what had happened and asked if something could be done to at lease get my necessary prescriptions filled. The nurse had to call me back after speaking with Dr. Cheng, Dr. Cheng asked me to come back in the office the follow week for discussion. Well I went in...Dr. Cheng was not as rude but again, seemed to have NO idea who I was. She proceeded to tell me that she thought I needed to have some tests run to see what exactly was causing my symptoms and that she did not want to medicate me for something SHE had no evidence I had, never mind the reports from Mayo, Johns Hopkins and the Cleveland Institute!! That was it for me...I was GONE! Found Dr. Guy Clark in Santa Barbara and have been seeing my ever-since. :) read more

Dr. Cheng is compassionate and caring and takes the time to listen and review tests and order X-rays, Chang meds, and work with me as a team to get to the bottom of my pain issues. She is up on the latest technology and encourages me to take care of myself. I would recommend her to anyone needing a rheumatologist! Fantastic! read more

I had an emergency break down this weekend with my knee and no one called me from her office to see what I could do to with my arthritis stabbing pain, she has never really liked treated me and her office staff is the worse ever so I called my insurance and changed arthritis doctor thank god the county got another arthritis doctor because when my dr Howard Hoos left I was so disappointed because when I went to see dr Tammy cheng she was so mean and didn't understand my pain and to get an appt was horrible like 2 months I think she just has too many patients that she just doesn't care about any of them, so I cancelled my appt with that horrible office and hope to be happy with my new doctor, I just don't want people think that there's not else but that horrible doctor. read more

Cheng was rude and awful. She claimed she did not have my previous rheumatologist records, though they had faxed them twice and mailed me a copy as well. She took me off of all of my medications (which had taken my docs before the move to CA 3 years of work to get me functional), did not care that the result was inflammation and incredible pain, told me it was fibromyalgia and that there was nothing she could do about that. My primary care doc remarked that my blood test showed high inflammation markers, Cheng said There was no indication of any problem (ignoring my description of the pain and showing her red and swollen joints.) i didn't have RA markers, so she ignored me, in a classic case of treating the test instead of the patient. When I aked her again about the pain, she told me I needed a psych referral. Then without giving me any direction, or ever seeing 3 years worth of previous records, said she would see me again in two months. Over my dead body. It was the single most awful medical experience I've had, and I cannot believe she is allowed to treat patients with chronic inflammation diseases. See *anybody* else. read more

My father has horrible arthritis. He has had 2 appointments with her and they have canceled his appointment the day of! Two times! Very irresponsible to treat my elderly father this way. No respect for his suffering. The staff is just as bad!! read more

When Dr. Cheng comes into the exam room, she always checks the notes of another doctor I see. I feel that it helps know what treatment she can add since they both come at the pain from two different practices. She listens to my concerns. The staff in Camarillo is helpful and efficient. read more

Dr Cheng was nice in the beginning but when she cannot figure out what is wrong with you she classifies you as Fibromyalgia and mild arthritis. Saw her for 2 years, and on last appointment I asked her about an MRI of my shoulder, explaining the excruciating pain.... She put her hand on my shoulder and said "I think your brain is playing tricks on you". I requested my records, found another Rheumatologist who did the MRI I requested and after more blood work, Diagnosed me with Rheumatoid Arthritis (the worst one) and also Ankylosing Spondilitis, a Auto Immune disease that causes my body to attack it's own joints and especially the spine , which by the way I have bulging discs so this makes it even more excruciating .. I just started taking Humira, a medication that tries to put your body in remission, it cannot however fix the damage of the last few years I wasted not being diagnosed but I look forward to feeling better in 4 to 6 months. I lost 2 years of my life due to this Doctor's mis-diagnosis . She does however smile to your face when she is calling you a liar on your pain symptoms. An added note, her nurse in Oxnard does not return phone calls. NOT ONCE in 2 years. I was left without a refill request for 7 days because she wanted to wait and ask me at my appointment. How about a phone call to say hey, don't bother calling the pharmacy and our office everyday, I am not going to do anything about your request. The front desk technician, Yolanda , is the only reason I give this place 1 star. She is very nice. read more

Dr. Cheng is highly skilled in her field and has sure put her mind to work on my rare disease. During her medical training, she specifically asked to have unusual cases referred to her, providing her with unique opportunities to study and treat rare diseases. Lucky me! She actually has experience treating several others like me. To maximize our time together, we each arrive with a short list of questions for each other. She is friendly, compassionate and reassuring, particularly given the brief time allotted for each patient visit in this busy clinic. read more

One of the worst experiences i have ever had in the medical industry, if not, ever!! I was referred to her by a Dr for a abnormality in my blood work. Upon entering she was upset that i didnt take my socks off! I took them off she asked why i was there i explained she then repeated the question with a attitude so i repeated the same answer. She said I dont help w headaches ( i was just explaining m situation like i thought she asked) told me to lay back tapped my stomach twice said nothing wrong see a Dr for your problems then walked out the door..Hellloo!!!! they referred me to you!! The nurse came back in and gave me paperwork for blood work for gonorrhea!!! I had joint pain and body aches!!!..i told the nurse i was furious and absolutely disgusted.. waste of a work day, even though it lasted 2 min max..idk who pissed in her cheerios this morning, but its great to know some people are getting 5 star treatment and others are getting disrespected! read more