Cirugía reconstructiva para el tratamiento de las úlceras por presión
Appendices
Appendix 1. Search strategies
The Cochrane Central Register of Controlled Trials (CENTRAL)
ID Search
#1 MeSH descriptor: [Surgical Procedures, Operative] explode all trees
#2 MeSH descriptor: [Surgical Flaps] explode all trees
#3 (surger* or surgical*) .ti
#4 (primary near/3 closure*):ti,ab,kw
#5 (skin near/3 (graft* or transplant*)):ti,ab,kw
#6 ((surg* or random or region* or muscle or musculocutaneous or fascial* or fasciocutaneous* or perforat* or free) near/2 flap*):ti,ab,kw
#7 "tissue expansion":ti,ab,kw
#8 {or #1‐#7}
#9 MeSH descriptor: [Pressure Ulcer] explode all trees
#10 (pressure next (ulcer* or sore* or injur*)):ti,ab,kw
#11 (decubitus next (ulcer* or sore*)):ti,ab,kw
#12 ((bed next sore*) or bedsore*):ti,ab,kw
#13 {or #9‐#12}
#14 {and #8, #13} in Trials
Ovid MEDLINE
1 exp surgical procedures, operative/
2 exp Surgical Flaps/
3 (surger* or surgical*).ti.
4 (primary adj3 closure*).ti,ab.
5 (skin adj3 (graft* or transplant*)).ti,ab.
6 ((surg* or reconstruct* or random or region* or muscle or musculocutaneous or fascial* or fasciocutaneous* or perforat* or free) adj2 flap*).ti,ab.
7 tissue expansion.ti,ab.
8 or/1‐7
9 exp Pressure Ulcer/
10 (pressure adj (ulcer* or sore* or injur*)).tw.
11 (decubitus adj (ulcer* or sore*)).tw.
12 (bedsore* or bed sore*).tw.
13 or/9‐12
14 and/8,13
15 randomized controlled trial.pt.
16 controlled clinical trial.pt.
17 randomi?ed.ab.
18 placebo.ab.
19 clinical trials as topic.sh.
20 randomly.ab.
21 trial.ti.
22 or/15‐21
23 exp animals/ not humans.sh.
24 22 not 23
25 and/14,24
26 limit 25 to ed=20160301‐20160926
Ovid Embase
1 exp surgical technique/
2 exp skin graft/
3 exp tissue flap/
4 exp tissue expansion/
5 (surger* or surgical*).ti.
6 (primary adj3 closure*).ti,ab.
7 (skin adj3 (graft* or transplant*)).ti,ab.
8 ((surg* or reconstruct* or random or region* or muscle or musculocutaneous or fascial* or fasciocutaneous* or perforat* or free) adj2 flap*).ti,ab. (26038)
9 tissue expansion.ti,ab.
10 or/1‐9
11 exp decubitus/
12 (pressure adj (ulcer* or sore* or injur*)).tw.
13 (decubitus adj (ulcer* or sore*)).tw.
14 (bedsore* or bed sore*).tw.
15 or/11‐14
16 10 and 15
17 Randomized controlled trials/
18 Single‐Blind Method/
19 Double‐Blind Method/
20 Crossover Procedure/
21 (random* or factorial* or crossover* or cross over* or cross‐over* or placebo* or assign* or allocat* or volunteer*).ti,ab. (1563193)
22 (doubl* adj blind*).ti,ab.
23 (singl* adj blind*).ti,ab.
24 or/17‐23
25 exp animals/ or exp invertebrate/ or animal experiment/ or animal model/ or animal tissue/ or animal cell/ or nonhuman/ (22565994)
26 human/ or human cell/
27 and/25‐26
28 25 not 27
29 24 not 28
30 and/16, 29
EBSCO CINAHL
S27S13 AND S26
S26S14 OR S15 OR S16 OR S17 OR S18 OR S19 OR S20 OR S21 OR S22 OR S23 OR S24 OR S25
S25TI allocat* random* or AB allocat* random*
S24MH "Quantitative Studies"
S23TI placebo* or AB placebo*
S22MH "Placebos"
S21TI random* allocat* or AB random* allocat*
S20MH "Random Assignment"
S19TI randomi?ed control* trial* or AB randomi?ed control* trial*
S18AB ( singl* or doubl* or trebl* or tripl* ) and AB ( blind* or mask* )
S17TI ( singl* or doubl* or trebl* or tripl* ) and TI ( blind* or mask* )
S16TI clinic* N1 trial* or AB clinic* N1 trial*
S15PT Clinical trial
S14MH "Clinical Trials+"
S13S7 AND S12
S12S8 OR S9 OR S10 OR S11
S11TI decubitus or AB decubitus
S10TI ( bed sore* or bedsore* ) or AB ( bed sore* or bedsore* )
S9TI ( pressure ulcer* or pressure sore* ) or AB ( pressure ulcer* or pressure sore* )
S8(MH "Pressure Ulcer+")
S7S1 OR S2 OR S3 OR S4 OR S5 OR S6
S6TI tissue expansion OR AB tissue expansion
S5TI ((surg* or reconstruct* or random or region* or muscle or musculocutaneous or fascial* or fasciocutaneous* or perforat* or free) N2 flap*) OR AB ((surg* or random or region* or muscle or musculocutaneous or fascial* or fasciocutaneous* or perforat* or free) N2 flap*)
S4TI (skin N3 (graft* or transplant*)) or AB (skin N3 (graft* or transplant*))
S3TI (primary N3 closure*) OR AB (primary N3 closure*)
S2TI surger* or surgical*
S1(MH "Surgery, Operative+")
Appendix 2. 'Risk of bias' assessment (individually randomised controlled trials)
1. Was the allocation sequence randomly generated?
Low risk of bias
The investigators describe a random component in the sequence generation process such as: referring to a random number table; using a computer random number generator; coin tossing; shuffling cards or envelopes; throwing dice; drawing of lots.
High risk of bias
The investigators describe a non‐random component in the sequence generation process. Usually, the description would involve some systematic, non‐random approach, for example: sequence generated by odd or even date of birth; sequence generated by some rule based on date (or day) of admission; sequence generated by some rule based on hospital or clinic record number.
Unclear
Insufficient information about the sequence generation process to permit judgement of low or high risk of bias.
2. Was the treatment allocation adequately concealed?
Low risk of bias
Participants and investigators enrolling participants could not foresee assignment because one of the following, or an equivalent method, was used to conceal allocation: central allocation (including telephone, web‐based and pharmacy‐controlled randomisation); sequentially numbered drug containers of identical appearance; sequentially numbered, opaque, sealed envelopes.
High risk of bias
Participants or investigators enrolling participants could possibly foresee assignments and thus introduce selection bias, such as allocation based on: use of an open random allocation schedule (e.g. a list of random numbers); assignment envelopes without appropriate safeguards (e.g. envelopes were unsealed, non‐opaque or not sequentially numbered); alternation or rotation; date of birth; case record number; any other explicitly unconcealed procedure.
Unclear
Insufficient information to permit judgement of low or high risk of bias. This is usually the case if the method of concealment is not described or not described in sufficient detail to allow a definite judgement, for example if the use of assignment envelopes is described, but it remains unclear whether envelopes were sequentially numbered, opaque and sealed.
3. Blinding ‐ was knowledge of the allocated interventions adequately prevented during the study?
Low risk of bias
Any one of the following:
-
No blinding, but the review authors judge that the outcome and the outcome measurement are not likely to be influenced by lack of blinding.
-
Blinding of participants and key study personnel ensured, and unlikely that the blinding could have been broken.
-
Either participants or some key study personnel were not blinded, but outcome assessment was blinded and the non‐blinding of others unlikely to introduce bias.
High risk of bias
Any one of the following:
-
No blinding or incomplete blinding, and the outcome or outcome measurement is likely to be influenced by lack of blinding.
-
Blinding of key study participants and personnel attempted, but likely that the blinding could have been broken.
-
Either participants or some key study personnel were not blinded, and the non‐blinding of others likely to introduce bias.
Unclear
Any one of the following:
-
Insufficient information to permit judgement of low or high risk of bias.
-
The study did not address this outcome.
4. Were incomplete outcome data adequately addressed?
Low risk of bias
Any one of the following:
-
No missing outcome data.
-
Reasons for missing outcome data unlikely to be related to true outcome (for survival data, censoring unlikely to be introducing bias).
-
Missing outcome data balanced in numbers across intervention groups, with similar reasons for missing data across groups.
-
For dichotomous outcome data, the proportion of missing outcomes compared with observed event risk not enough to have a clinically relevant impact on the intervention effect estimate.
-
For continuous outcome data, plausible effect size (difference in means or standardised difference in means) among missing outcomes not enough to have a clinically relevant impact on observed effect size.
-
Missing data have been imputed using appropriate methods.
High risk of bias
Any one of the following:
-
Reason for missing outcome data likely to be related to true outcome, with either imbalance in numbers or reasons for missing data across intervention groups.
-
For dichotomous outcome data, the proportion of missing outcomes compared with observed event risk enough to induce clinically relevant bias in intervention effect estimate.
-
For continuous outcome data, plausible effect size (difference in means or standardised difference in means) among missing outcomes enough to induce clinically relevant bias in observed effect size.
-
'As‐treated' analysis done with substantial departure of the intervention received from that assigned at randomisation.
-
Potentially inappropriate application of simple imputation.
Unclear
Any one of the following:
-
Insufficient reporting of attrition/exclusions to permit judgement of low or high risk of bias (e.g. number randomised not stated, no reasons for missing data provided).
-
The study did not address this outcome.
5. Are reports of the study free of suggestion of selective outcome reporting?
Low risk of bias
Any of the following:
-
The study protocol is available and all of the study's pre‐specified (primary and secondary) outcomes that are of interest in the review have been reported in the pre‐specified way.
-
The study protocol is not available but it is clear that the published reports include all expected outcomes, including those that were pre‐specified (convincing text of this nature may be uncommon).
High risk of bias
Any one of the following:
-
Not all of the study's pre‐specified primary outcomes have been reported.
-
One or more primary outcomes are reported using measurements, analysis methods or subsets of the data (e.g. subscales) that were not pre‐specified.
-
One or more reported primary outcomes were not pre‐specified (unless clear justification for their reporting is provided, such as an unexpected adverse effect).
-
One or more outcomes of interest in the review are reported incompletely so that they cannot be entered in a meta‐analysis.
-
The study report fails to include results for a key outcome that would be expected to have been reported for such a study.
Unclear
Insufficient information to permit judgement of low or high risk of bias. It is likely that the majority of studies will fall into this category.
6. Other sources of potential bias
Low risk of bias
The study appears to be free of other sources of bias.
High risk of bias
There is at least one important risk of bias. For example, the study:
-
had a potential source of bias related to the specific study design used; or
-
has been claimed to have been fraudulent; or
-
had some other problem.
Unclear
There may be a risk of bias, but there is either:
-
insufficient information to assess whether an important risk of bias exists; or
-
insufficient rationale or evidence that an identified problem will introduce bias.
Appendix 3. 'Risk of bias' assessment (cluster‐randomised controlled trials)
In cluster‐randomised trials, particular biases to consider include: (i) recruitment bias; (ii) baseline imbalance; (iii) loss of clusters; (iv) incorrect analysis; and (v) comparability with individually randomised trials.
(i) Recruitment bias can occur when individuals are recruited to the trial after the clusters have been randomised, as the knowledge of whether each cluster is an 'intervention' or 'control' cluster could affect the types of participants recruited.
(ii) Cluster‐randomised trials often randomise all clusters at once, so lack of concealment of an allocation sequence should not usually be an issue. However, because small numbers of clusters are randomised, there is a possibility of chance baseline imbalance between the randomised groups, in terms of either the clusters or the individuals. Although not a form of bias as such, the risk of baseline differences can be reduced by using stratified or pair‐matched randomisation of clusters. Reporting of the baseline comparability of clusters, or statistical adjustment for baseline characteristics, can help reduce concern about the effects of baseline imbalance.
(iii) Occasionally complete clusters are lost from a trial, and have to be omitted from the analysis. Just as for missing outcome data in individually randomised trials, this may lead to bias. In addition, missing outcomes for individuals within clusters may also lead to a risk of bias in cluster‐randomised trials.
(iv) Many cluster‐randomised trials are analysed by incorrect statistical methods, not taking the clustering into account. Such analyses create a 'unit of analysis error' and produce over‐precise results (the standard error of the estimated intervention effect is too small) and P values that are too small. They do not lead to biased estimates of effect. However, if they remain uncorrected, they will receive too much weight in a meta‐analysis.
(v) In a meta‐analysis including both cluster and individually randomised trials, or including cluster‐randomised trials with different types of clusters, possible differences between the intervention effects being estimated need to be considered. For example, in a vaccine trial of infectious diseases, a vaccine applied to all individuals in a community would be expected to be more effective than if the vaccine was applied to only half of the people. Another example is provided by a Cochrane review of hip protectors. The cluster trials showed large positive effect whereas individually randomised trials did not show any clear benefit. One possibility is that there was a 'herd effect' in the cluster‐randomised trials (which were often performed in nursing homes, where compliance with using the protectors may have been enhanced). In general, such 'contamination' would lead to underestimates of effect. Thus, if an intervention effect is still demonstrated despite contamination in those trials that were not cluster‐randomised, a confident conclusion about the presence of an effect can be drawn. However, the size of the effect is likely to be underestimated. Contamination and 'herd effects' may be different for different types of cluster.
