Table 2.
Downs and Black quality assessment summary.
| Author, year | |||||
| Barry, 2012 [150] | Friedman, 2014 [148] | Knutson, 2016 [151] | Prange-Lasonder 2017 [149] | ||
| Reporting | |||||
| 1a | 1 | 1 | 1 | 1 | |
| 2b | 1 | 1 | 1 | 1 | |
| 3c | 1 | 1 | 1 | 1 | |
| 4d | 1 | 1 | 1 | 1 | |
| 5e | 2 | 2 | 2 | 2 | |
| 6f | 1 | 1 | 1 | 1 | |
| 7g | 1 | 1 | 1 | 0 | |
| 8h | 0 | 0 | 1 | 0 | |
| 9i | 1 | 0 | 1 | 0 | |
| 10j | 1 | 1 | 1 | 1 | |
| External validity | |||||
| 11k | 0 | 1 | 0 | 0 | |
| 12l | 0 | 1 | 0 | 0 | |
| 13m | 0 UTDn | 0 UTD | 0 UTD | 0 UTD | |
| Internal validity—bias | |||||
| 14o | 0 | 1 | 0 | 0 | |
| 15p | 1 | 1 | 1 | 0 | |
| 16q | 1 | 1 | 1 | 1 | |
| 17r | 0 N/As | 1 | 1 | 1 | |
| 18t | 1 | 1 | 1 | 1 | |
| 19u | 0 UTD | 1 | 1 | 0 UTD | |
| 20v | 1 | 1 | 1 | 1 | |
| Internal validity—confounding (section bias) | |||||
| 21w | 0 UTD | 1 | 1 | 1 | |
| 22x | 0 UTD | 0 UTD | 0 UTD | 0 UTD | |
| 23y | 1 | 1 | 1 | 1 | |
| 24z | 0 UTD | 1 | 0 UTD | 0 UTD | |
| 25aa | 0 UTD | 0 UTD | 0 UTD | 0 UTD | |
| 26ab | 1 | 0 UTD | 1 | 0 UTD | |
| Power | |||||
| 27ac | 0 | 0 | 0 | 0 | |
| Total | 16 | 21 | 20 | 14 | |
a1: Clarity of aims, objectives, and hypothesis.
b2: Clarity of main outcomes described.
c3: Clarity of participant characteristics.
d4: Clarity of intervention description.
e5: Clarity of distributions of principal confounders in each group.
f6: Are the main findings of the study clearly described?
g7: Are estimates of random variability in data for main outcomes clearly described?
h8: Have all adverse effects related to the intervention been reported?
i9: Have lost to follow-up participant characteristics been described?
j10: Have probability values for main outcomes been reported except from where P<.001?
k11: Were the participants asked to take part in the study representative of the entire population from which they were recruited?
l12: Were the participants prepared to take part in the study representative of the population from which they were recruited?
m13: Were the staff, places, and facilities where the participants were treated representative of the treatment that the majority of patients receive?
nUTD: unable to determine.
o14: Was there an attempt to blind participants?
p15: Was there an attempt to blind those measuring the main outcomes of the intervention?
q16: If any study results were based on data dredging, was this made clear?
r17: In trials and cohort studies, do the analysis adjust for different lengths of follow-up of participants, or in case-control studies, is the time period between the intervention and outcome the same for cases and controls?
sNot applicable.
t18: Were the statistical tests used to assess the main outcomes appropriate?
u19: Was intervention compliance reliable?
v20: Were the main outcome measures used accurate (valid and reliable)?
w21: Were the participants in different intervention groups (trials and cohort studies) or were the cases and controls (case-control studies) recruited from the same population?
x22: Were the participants in different intervention groups (trials and cohort studies) or were the cases and controls (case-control studies) recruited over the same period of time?
y23: Were participants randomized to the intervention groups?
z24: Was the randomized intervention assignment concealed from both participants and health care staff until recruitment was complete and irrevocable?
aa25: Was there adequate adjustment for confounding in the analysis from which the main findings were drawn?
ab26: Were losses to follow-up taken into account?
ac27: Did the study have sufficient power to detect a clinically important effect?