Ludington‐Hoe 2005.
| Methods | Randomized cross‐over trial | |
| Participants | 24 preterm infants (< 37 weeks PMA); results from 23 infants Postnatal age, mean ± SD, days: 22 ± 11.4 Painful procedure: heel lance Study period: unclear |
|
| Interventions | Intervention: 3 hours of skin‐to‐skin care before and during painful procedure Control: standard care during painful procedure Provider: mother |
|
| Outcomes | Heart rate, respiratory rate, oxygen saturation, cry duration, behavioural state | |
| Notes | Country: El Salvador and USA Power calculation: yes |
|
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | "The cross‐over design controlled for all threats to internal validity except the interaction of selection and treatment, but assignment to group A or B independently and randomly by the Zellen technique insured balanced representation in both treatment sequences." |
| Allocation concealment (selection bias) | Unclear risk | "Consenting mother‐infant pairs were randomised by sealed envelope technique into 2 groups" It is not specified whether envelopes were sealed. opaque and sequentially numbered |
| Blinding (performance bias and detection bias) All outcomes | High risk | "...the observers were not blind to treatment and group, a condition that is being corrected by having all data videotaped and computer‐stored for scoring outside the clinical area in an ongoing study." |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Dropout rates explained |
| Selective reporting (reporting bias) | Low risk | All outcomes are clearly presented in Tables 2, 3 |
| Other bias | High risk | "Each infant was tested on one day using this cross‐over design that controlled for intra‐ and inter‐subject variability and provided the highest possible equivalence among subjects exposed to both conditions. The cross‐over design controlled for all threats to internal validity except the interaction of selection and treatment, but assignment to group A or B independently and randomly by the Zellen technique insured balanced representation in both treatment sequences. Carry‐over effects from one condition to the next is a concern with any cross‐over design; previous KC research has shown that physiological and behavioral state effects of KC are not sustained long after KC is discontinued, making 3‐4 hours sufficient to minimize carry‐over effects." In Zellen's technique, patients are randomized before consent occurs; therefore in theory, consent can be sought conditionally |