本帖最後由 yanjw2000 於 2010-1-25 20:48 編輯
作者：Laurie Barclay, MD
出處：WebMD醫學新聞
January 11, 2010 — 根據1月號小兒與青少年醫學誌(Archives of Pediatrics & Adolescent Medicine)中配對之病例對照研究結果，父母親拒絕水痘疫苗會讓小孩的水痘風險增加9倍。
科羅拉多州丹佛Kaiser Permanente健康研究中心的Jason M. Glanz博士等人寫道，擴大孩童免疫要求以及增加疫苗和慢性疾病之間的覆蓋範圍，也提高了父母親有關疫苗安全性的關心，有父母親認為孩童的感染風險低、許多使用疫苗預防的疾病並不嚴重。因此，過去10年間，向學校之接種要求提出非醫療原因之免除請求的父母親明顯增加。
本研究目標是，對於拒絕水痘疫苗接種之父母親的小孩，以個人基礎量化因水痘感染而需要醫療照護的風險有多大，1998至2008年間，「Kaiser Permanente of Colorado(KPCO)」健康計畫中，由醫師診斷的小兒水痘疫苗案例(n = 133人)，依照年紀、性別、與納入KPCO的時間，和4個隨機選擇的控制組對象(n = 493人)配對。
此研究的初級終點為水痘感染，主要曝露因素為拒絕水痘疫苗，使用條件式邏輯迴歸分析。
案例病患中，7個(5%)是水痘疫苗拒絕者，控制組有3個(0.6%)，相較於父母親接受疫苗的小孩，父母親拒絕水痘疫苗接種的小孩，因為水痘感染而需要醫療照護的風險大幅增加(勝算比[OR]為8.6；95%信心區間[CI]為2.2 - 33.3；P= .004)。
考量整個KPCO健康計畫的小兒族群時，5%水痘案例可以歸因於父母親拒絕疫苗。
研究作者寫道，父母親拒絕水痘疫苗接種的孩童，水痘感染風險高於接種的孩童。這些結果將有助於健康照護提供者以及父母親做出有關孩童免疫方面的決定。
研究限制包括，一般化程度有限，因為只是從科羅拉多州的一個健康照護計畫中選出研究對象，如果醫師對於未接種的小孩比較可能做出水痘診斷，則會有診斷偏見，拒絕疫苗比率低，沒有足夠的統計強度來評估1998到200年間拒絕疫苗和感染水痘之間的關聯。再者，案例控制設計無法計算父母親拒絕疫苗之比率隨著時間的變化，輕微而無需就醫的水痘案例也可能被忽略了。
他們結論表示，有些父母親認為，未接種疫苗的孩童對於這些可用疫苗預防的疾病並無風險，這些結果提供了這是錯誤認知的證據，在美國，拒絕疫苗的情況增加，健康照護提供者應以一個獨立可信的立場來影響接種疫苗的行為。我們相信，這個資訊對醫師和病患進行免疫諮商是有幫助的。
本研究有部份資金接受國家過敏與感染症研究中心支持，部份來自Kaiser Permanente Colorado健康研究中心，研究作者們皆宣告沒有相關財務關係。
Arch Pediatr Adolesc Med. 2010;164:66-70.
Parental Varicella Vaccination Refusal Increases Risk for Unvaccinated Children
By Laurie Barclay, MD
Medscape Medical News
January 11, 2010 — Parental refusal of varicella vaccination puts unvaccinated children at a 9-fold greater risk for varicella, according to the results of a matched case-control study reported in the January issue of the Archives of Pediatrics & Adolescent Medicine.
"Expanding childhood immunization requirements and increased media coverage of alleged associations between vaccinations and chronic illnesses have heightened parental concerns regarding vaccine safety," write Jason M. Glanz, PhD, from Kaiser Permanente Institute for Health Research in Denver, Coloradio, and colleagues. "Parents have also expressed concerns that children are at low risk of infection and that many vaccine-preventable diseases are not serious. During the last decade, as a consequence, the number of parents who claimed non-medical exemptions to school immunization requirements has increased significantly."
The goal of this study was to quantify individual-level as well as attributable risk for varicella infection requiring medical care in children whose parents refuse varicella immunizations. Between 1998 and 2008 at Kaiser Permanente of Colorado (KPCO) health plan, each pediatric varicella case diagnosed by a physician (n = 133) was matched by age, sex, and length of enrollment in KPCO to 4 randomly selected control subjects (n = 493).
The primary endpoint of the study was varicella infection, with the main exposure being refusal of varicella vaccine, analyzed with conditional logistic regression analysis.
Among the case patients, there were 7 varicella vaccine refusers (5%) vs 3?refusers (0.6%) among the control subjects. Compared with children of parents who accepted vaccinations, children of parents who refused varicella immunizations were at greatly increased risk of varicella infection requiring medical care (odds ratio [OR], 8.6; 95% confidence interval [CI], 2.2 - 33.3; P?= .004).
Considering the entire KPCO pediatric population, 5% of varicella cases could be attributed to parental vaccine refusal.
"Children of parents who refuse varicella immunizations are at high risk of varicella infection relative to vaccinated children," the study authors write. "These results will be helpful to health care providers and parents when making decisions about immunizing children."
Limitations of this study include limited generalizability because the study population was selected from a single managed healthcare plan in Colorado, diagnostic bias if physicians are more likely to make a diagnosis of varicella in unvaccinated children, low rate of vaccine refusal, and insufficient statistical power to evaluate the association between vaccine refusal and varicella infection by year from 1998 to 2008. Furthermore, the case-control design did not permit calculation of parental vaccine refusal rates with time, and mild cases of varicella that did not come to medical attention may have been missed.
"These results provide evidence to counter the misperception among some parents that unvaccinated children are not at risk for vaccine-preventable diseases," they conclude. "As vaccine refusal increases in the United States, health care providers are in a uniquely trusted position to influence immunization behavior. We believe this information will be useful to physicians who counsel patients about immunizations."
This study was supported in part by a grant from the National Institute of Allergy and Infectious Diseases and in part by Kaiser Permanente Colorado Institute for Health Research. The study authors have disclosed no relevant financial relationships.
Arch Pediatr Adolesc Med. 2010;164:66-70. |
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