formulas, tables, and charts in Chapter 25 and on the book’s Cheat Sheet at www.dummies.com (just

search for “Biostatistics For Dummies Cheat Sheet”).

You must also allow some extra space in your target sample-size estimate for some of the

enrolled participants to drop out or otherwise not contribute the data you need for your analysis.

For example, suppose that you need full data from 64 participants for sufficient statistical power

to answer your main objective. If you expect a 15 percent attrition rate from the study, which

means you expect only 85 percent of the enrolled participants to have analyzable data, then you

need to plan to enroll 64/0.84, or 76, participants in the study.

Assembling the study protocol

A study protocol (or just protocol) is a document that lays out exactly what you plan to do to collect

and analyze data in a research study. For ethical reasons, every research study involving human

participants should have a protocol, and for other types of studies, having a protocol prepared before

starting the research is considered best practices. In a clinical trial, the protocol is especially

important because the participants are being assigned to interventions by the researcher, and there is

often double-blinding and randomization.

In terms of standard elements, a formal drug clinical trial protocol typically contains these

components:

Title: A title conveys as much information about the trial as you can fit into one sentence, including

the protocol ID, name of the study, clinical phase, type and structure of trial, type of randomization

and blinding, name of the drug or drugs being tested, treatment regimen, intended effect, and the

population being studied (which could include a reference to individuals with a particular medical

condition). A title can be quite long — this example title has all the preceding elements:

Protocol BCAM521-13-01 (ASPIRE-2) — a Phase-IIa, double-blind, placebo-controlled,

randomized, parallel-group study of the safety and efficacy of three different doses of AM521,

given intravenously, once per month for six months, for the relief of chronic pain, in adults with

knee osteoporosis.

Background information: This section includes information about the disease for which the drug

is an intended treatment. It includes the epidemiology (the condition’s prevalence and impact), and

its known physiology down to the molecular level. It also includes a review of treatments currently

available (if any), and information about the drug or drugs being tested, including mechanism of

action, the results of prior testing, and known and potential risks and benefits to participants.

Rationale: The rationale for the study states why it makes sense to do this study at this time and

includes a justification for the choice of doses, how the drug is administered (such as orally or

intravenously), duration of drug administration, and follow-up period.

Aims, objectives, and hypotheses: We discuss these items in the earlier section “Identifying aims,

objectives, hypotheses, and variables.”

Detailed descriptions of all inclusion, exclusion, and withdrawal criteria: See the earlier section

“Deciding who is eligible for the study” for more about these terms.