無關節穿刺術的情況下改善痛風診斷


  【24drs.com】2010年時有一規定,原本是為了在一線照護對象中診斷痛風,現在,這規定也可適用於單關節炎患者的二線照護,適用於無法分析關節液時,顯示可改善這些情況下之痛風臨床診斷的預測價值。
  
  未參與本項研究的俄亥俄州克里夫蘭診所風濕科Howard Smith醫師表示,滑液分析是痛風診斷的黃金標準,但是通常無法獲得這個檢體,或者沒有適當的顯微鏡可用;而這個診斷工具相當容易使用,有助於迅速與正確診斷痛風。
  
  2010年時,一組風濕科專家在荷蘭首度提出診斷規則且報告了用於一線照護患者的效度,受試者操作特徵曲線下面積為0.85 (95%信心區間0.81 - 0.90)。
  
  荷蘭Rijnstate醫院風濕科Laura B.E. Kienhorst醫師等人,在9月16日的Rheumatology期刊線上發表一篇文章指出, 這項規則可以用來診斷二線照護病患的痛風。
  
  在這篇研究中,單關節炎病患(n = 390人)先以該診斷規則診斷,之後抽取關節液分析有無出現單鈉尿酸鹽結晶,追蹤患者最長達17個月。
  
  發現有這些結晶的病患(n = 219人)被分類為有痛風,即便這些結晶是在開始時之診斷後數月發現,如果關節穿刺未獲得足夠關節液(n = 12人),病患被分類為無痛風。
  
  作者們寫道,我們的診斷研究優勢是,這是具有長追蹤期的前瞻式設計,對這些無特定關節炎的病患在有任何關節炎時進行再度評估。未排除無特定關節炎則與臨床實務一致,未特定之單關節炎是相當常見的。不過,他們也指出,這篇研究沒有充分做到雙盲。
  
  研究者報告指出,分數8分以上者為正預測值0.87,分數4分以下者為負預測值0.95。他們計算了這個診斷規則的受試者操作特徵曲線下面積值為0.86 (95%信心區間0.82 - 0.89)。
  
  這個診斷規則得分4分以下代表痛風的可能性低,建議醫師考慮痛風之外的診斷。
  
  Kienhorst醫師解釋,當這個診斷規則發現高可能性時,醫師們可將病患視為有痛風而治療。但是當不確定診斷(可能性中等)時,需讓病患就診風濕科諮商,以進行關節液分析或者廣泛追蹤。建議醫師對每個復發關節炎病患進行複查,因為,如果病患是被偽陽性分類為痛風,往往會有忽略其他重要風濕診斷的風險。
  
  以前的研究比較了單鈉尿酸鹽結晶的黃金標準與美國風濕科學院的痛風病患分類準則,發現效度有限,所以特別需要正預測值和負預測值效度高的診斷規則。
  
  資料來源:http://www.24drs.com/professional/list/content.asp?x_logon=W&x_idno=7121&x_classno=0
  

Improved Gout Diagnosis in the Absence of Arthrocentesis

By Lara C. Pullen, PhD
Medscape Medical News

A 2010 rule that was originally designed to diagnose gout in the primary care population has now been shown to perform equally well in a secondary care population of patients with monoarthritis. The rule is used when joint fluid analysis is not an option, and it has been shown to improve the predictive value of the clinical diagnosis of gout under these circumstances.

"Synovial fluid analysis is the gold standard for the diagnosis of gout, but often fluid is not readily obtainable or able to be viewed under an appropriate microscope. This diagnostic tool is easy to use and will provide help in the rapid and correct diagnosis of gout," Howard Smith, MD, a rheumatologist at the Cleveland Clinic in Ohio, told Medscape Medical News. Dr Smith was not involved in the study.

In 2010, a team of rheumatologists in the Netherlands first described the diagnostic rule and reported its validity in primary care patients with an area under the receiver operator characteristic curve of 0.85 (95% confidence interval, 0.81 - 0.90).

Validation in Secondary Care Population

Laura B.E. Kienhorst, MD, from the Department of Rheumatology at Rijnstate Hospital in the Netherlands, and colleagues describe the ability of the rule to diagnose gout in a secondary care population of patients in an article published online September 16 in Rheumatology.

In the current study, patients with monoarthritis (n = 390) were first diagnosed according to the diagnostic rule, and then their joint fluid was aspirated and analyzed for the presence of monosodium urate crystals. Patients were followed for up to 17 months.

Patients who were found to have these crystals (n = 219) were classified as having gout, even if the crystals were detected months after the baseline diagnosis. When arthrocentesis yielded inadequate joint fluid (n = 12), patients were classified as nongout.

"A strength of our diagnostic study is the prospective design with a long follow-up period in which patients with unspecified arthritis were re-evaluated in the case of any new arthritis. Not excluding patients with unspecified arthritis is consistent with clinical practice in which unspecified monoarthritis is prevalent," the authors write. They also note, however, that the study was not fully blinded.

The investigators report that a score of 8 points or higher had a positive predictive value of 0.87, and a score 4 or fewer points had a negative predictive value of 0.95. They calculated the area under the receiver operating characteristic curve for the diagnostic rule to be 0.86 (95% confidence interval, 0.82 - 0.89).

Rule Helps Diagnose Gout

A score of 4 or lower from the diagnostic rule indicates a low probability of gout and directs the practitioner to consider a diagnosis other than gout.

"When it [the rule] indicates a high probability, the physician can treat the patient as having gout. But when there is uncertainty (an intermediate probability) about the diagnosis, the patient would require a consultation with a rheumatologist for joint fluid analysis or extensive follow-up. Physician reexamination of every patient is advisable in the case of a recurrent arthritis because there always remains a risk of missing other important rheumatic diagnoses if patients are false-positively classified as gout," elaborated Dr Kienhorst.

Previous studies have compared the gold standard of monosodium urate crystals with the American College of Rheumatology criteria for classifying patients with gout and revealed limited validity, making the high positive predictive value and negative predictive value for the diagnostic rule especially noteworthy.

The authors and Dr Smith have disclosed no relevant financial relationships.

Rheumatology. Published online September 16, 2014.

    
相關報導
關節炎加重了其他慢性疾病的影響
2015/6/29 上午 09:22:26
長期治療痛風不佳
2015/1/6 上午 10:04:34
手部骨關節炎:可用MRI預測病程進展
2014/9/26 下午 05:44:10

上一頁
   1   2   3   4   5   6   7   8   9   10  




回上一頁