前瞻性研究
前瞻性的研究(prospective study)是以現(xiàn)在為起點(diǎn)追蹤到將來的研究方法，可彌補(bǔ)回顧性研究的缺陷。例如臨床心理學(xué)實(shí)驗(yàn)中，對一批A型行為類型者使用自我行為管理策略指導(dǎo)，并追蹤此后整個行為干預(yù)策略實(shí)施過程中被A型行為的改變情況，從而證明這種治療技術(shù)的實(shí)際效果。（百度）
A prospective study watches for outcomes, such as the development of a disease, during the study period and relates this to other factors such as suspected risk or protection factor(s). The study usually involves taking a cohort of subjects and watching them over a long period. The outcome of interest should be common; otherwise, the number of outcomes observed will be too small to be statistically meaningful (indistinguishable from those that may have arisen by chance). All efforts should be made to avoid sources of bias such as the loss of individuals to follow up during the study. Prospective studies usually have fewer potential sources of bias and confounding than retrospective studies.
回顧性研究
回顧性研究就是以現(xiàn)在為結(jié)果，回溯過去的研究方法。例如對已經(jīng)患有肺癌的患者和正常人群進(jìn)行分析，比較他們之前生活方式有什么不同，從而找出可能導(dǎo)致肺癌的危險(xiǎn)因素。這一研究方式由于條件限制較少，有其優(yōu)點(diǎn)，但其缺陷是被試目前的身心狀態(tài)會影響對過去資料報(bào)告的真實(shí)性和準(zhǔn)確性。
A retrospective study looks backwards and examines exposures to suspected risk or protection factors in relation to an outcome that is established at the start of the study. Many valuable case-control studies, such as Lane and Claypon's 1926 investigation of risk factors for breast cancer, were retrospective investigations. Most sources of error due to confounding and bias are more common in retrospective studies than in prospective studies. For this reason, retrospective investigations are often criticised. If the outcome of interest is uncommon, however, the size of prospective investigation required to estimate relative risk is often too large to be feasible. In retrospective studies the odds ratio provides an estimate of relative risk. You should take special care to avoid sources of?bias?and?confounding?in retrospective studies.
病例對照研究
Case-Control studies
outcome is measured before exposure
controls are selected on the basis of not having the outcome
good for rare outcomes
relatively inexpensive
smaller numbers required
quicker to complete
prone to selection bias
prone to recall/retrospective bias
related methods are?risk (retrospective),?chi-square 2 by 2 test,?Fisher's exact test,?exact confidence interval for odds ratio,?odds ratio meta-analysis?and?conditional logistic regression.
隊(duì)列研究
Cohort studies
Cohort studies are usually but not exclusively prospective, the opposite is true for case-control studies. The following notes relate cohort to case-control studies:
outcome is measured after exposure
yields true incidence rates and relative risks
may uncover unanticipated associations with outcome
best for common outcomes
expensive
requires large numbers
takes a long time to complete
prone to attrition bias (compensate by using?person-time?methods)
prone to the bias of change in methods over time
related methods are?risk (prospective),?relative risk meta-analysis,?risk difference meta-analysis?and?proportions
