Page 17 - An Evidence Review of Active Surveillance in Men With Localized Prostate Cancer

All five EPC team members participated in screening and selecting studies. An iterative
screening process was used for training and to ensure consistency in application of eligibility
criteria. Abstracts were screened once. A very low threshold was used to mark a study as of
possible interest. During full-text screening, equivocal articles were screened by at least two
team members.

Data Extraction

We extracted bibliographic data, eligibility criteria, enrollment years, study duration, and
sample size for all studies. For Key Question 1, we extracted data that allowed reconstruction of
trends over time in incidence and mortality, as well as patient-, tumor-, and system-level
characteristics of interest. We extracted data into tables of 5-year bins (e.g., 1980-84, 1985-89)
from 1980 to 2010. We extracted reported statistical data regarding changes over time in factors
of interest. For Key Question 2, we extracted data on patient- and tumor-level characteristics
used as eligibility criteria, followup or monitoring parameters, and specific triggers for definitive
treatment. We also extracted definitions of disease progression. For quantitative studies
(multivariable models) related to Key Question 3, we extracted the definition of the
observational strategy, factors of interest, and effect sizes. For qualitative studies (surveys)
related to Key Question 3, we extracted the specific survey approach used, the definition of the
observational strategy addressed, the qualitative summary of the key study findings, and
information to assess the study validity (e.g., survey response rate, survey validation). For Key
Question 4, we extracted details about the study population (including eligibility criteria and
baseline characteristics), specific interventions compared, outcome definitions, study design, and
effect sizes of outcomes of interest.

Quality Assessment
We formally assessed methodological quality only for studies included for Key Question 4.
Studies were graded using standard AHRQ EPC methodology with a three-level grading system
(A, B, or C). For RCTs, we primarily considered the methods used for randomization, allocation
concealment, and blinding, as well as the use of intention-to-treat analysis, the report of dropout
rate, and the extent to which valid primary outcomes were described and clearly reported. Only
RCTs and prospective comparative studies could receive an A grade. Retrospective studies could
be graded either B or C. For all studies, we used the following in our assessment (as applicable):
the report of eligibility criteria, the similarity of the comparative groups in terms of baseline
characteristics and prognostic factors, the report of intention-to-treat analysis, important
differential loss to followup between the comparative groups or overall high loss to followup,
and the validity and adequacy of the description of outcomes and results. Quality A studies are
those judged to have the least likelihood of bias and are considered the most internally valid.
Quality C studies have a substantial risk of bias and may not be valid. Quality assessment was
performed by the team member responsible for primary data extraction. The quality grade was
confirmed by at least one other team member.

Data Synthesis

All included study data were tabulated into summary tables (provided in the report
appendixes) that succinctly describe the important study characteristics and their findings. Time-
trend data for Key Question 1 were graphed over the interval of interest (1980–2010). Although

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