Table 2.
Characteristics of 123 articles reporting results of group-randomized trials in cancer research in peer-reviewed journals during the period 2011–2015, inclusive.
| Characteristic | N | % |
|---|---|---|
| Number of Study Conditions | ||
| Two | 109 | 88.6 |
| Three | 9 | 7.3 |
| Four or more | 5 | 4.1 |
| Design | ||
| Cohort | 94 | 76.4 |
| Cross-sectional | 26 | 21.1 |
| Combination of Cohort and Cross-sectional | 3 | 2.4 |
| Type of Randomization | ||
| Restricted Randomization | 67 | 54.5% |
| Matching only | 16 | 13.0 |
| Stratification only | 46 | 37.4 |
| Constrained Randomization only | 2 | 1.6 |
| Matching and Stratification | 3 | 2.4 |
| Simple or Unrestricted Randomization | 56 | 45.5 |
| Type of Group | ||
| Churches | 6 | 4.9 |
| Communities, Neighborhoods or Community Groups | 15 | 12.2 |
| Families | 4 | 3.3 |
| Housing Projects or Apartment Buildings | 1 | 0.8 |
| Clinicians, Provider Groups, Hospitals | 65 | 52.8 |
| Schools, Classes, Day Care Centers | 24 | 19.5 |
| Time perioda | 4 | 3.3 |
| Worksites | 4 | 3.3 |
| Average Number of Groups per Condition in the Analysis | ||
| 1 Group | 0 | 0.0 |
| 2–5 Groups | 3 | 2.4 |
| 6–8 Groups | 9 | 7.3 |
| 9–12 Groups | 16 | 13.0 |
| 13–24 Groups | 31 | 25.2 |
| ≥ 25 Groups | 58 | 47.2 |
| Variable | 1 | 0.8 |
| not reported | 5 | 4.1 |
| Average Number of Members per Group in the Analysis | ||
| <10 Members | 30 | 24.4 |
| 10–49 Members | 44 | 35.8 |
| 50–99 Members | 19 | 15.4 |
| ≥100 Members | 25 | 20.3 |
| not reported | 5 | 4.1 |
| Number of Time Points in the Analysis | ||
| 1 Time point | 94 | 76.4 |
| 2 Time points | 21 | 17.1 |
| 3–9 Time points | 8 | 6.5 |
| Focus of Study | ||
| Primary Prevention | 45 | 36.6 |
| Secondary Prevention | 54 | 43.9 |
| Tertiary Prevention | 24 | 19.5 |
| Target Population | ||
| Individuals with no personal history of the target cancer | 33 | 26.8 |
| Cancer survivors during primary treatment | 11 | 8.9 |
| Cancer survivors after primary treatment | 5 | 4.1 |
| Unknown or mixed cancer survivorship | 74 | 60.2 |
| Primary Outcome Variables | ||
| Alcohol Use | 3 | 2.4 |
| Delivery of Health Services | 22 | 17.9 |
| Dietary Variables | 9 | 7.3 |
| Fatigue | 0 | 0.0 |
| Incidence of Cancer | 4 | 3.3 |
| Knowledge of Cancer or Attitudes Regarding Cancer | 10 | 8.1 |
| Lymphedema | 0 | 0.0 |
| Mortality from Cancer | 1 | 0.8 |
| Neuropathy | 0 | 0.0 |
| Pain | 3 | 2.4 |
| Physical Activity | 5 | 4.1 |
| Quality of Life | 6 | 4.9 |
| Screening | 33 | 26.8 |
| Sun Protection | 3 | 2.4 |
| Tobacco Use | 10 | 8.1 |
| Weight | 1 | 0.8 |
| Other | 13 | 10.6 |
a
Some studies randomized time periods. For example, some clinic-based studies randomized blocks of six weeks to study conditions, so that patients who saw their provider were given the treatment randomly assigned to their time block. This work was performed in Bethesda Maryland during 2016–17.