Table 2 Methodological quality rating
Design of study | Â Possible points |
  Experimental: randomized controlled trial (RCT), random allocation; case-controlled trial (CCT), quasi-random allocation; three data collection points before and after the intervention | 1 |
  Quasi-experimental: controlled before-and-after study; comparable control sites | 1 |
  Quasi-experimental: non-equivalent control sites | 0 |
  Single group before-and-after tests with baseline measurements | 0 |
Content | Â |
  Intervention is clearly described | 1 |
Sample size | Â |
  An n per group sufficient to detect a significant effect (P < 0.05) with a power of 0.80 or reported calculation of power | 1 |
  An n per group insufficient to detect a significant effect (P < 0.05) with a power of 0.80 or no reported calculation of power | 0 |
Validity and reliability of instruments | Â |
  Unobtrusive observations, procedure described | 2 |
  Unobtrusive observations, procedure not described | 1 |
  Obtrusive observations, procedure described | 1 |
  Obtrusive observations, procedure not described | 0 |
Test statistics | Â |
  Test statistics are described | 1 |
Significance | Â |
  P value or confidence interval is given | 1 |