The main finding that emerged from this meta-analysis is that clinical pathways can effectively improve the quality of the care provided to the patients undergoing JR. The clinical pathways improved the analysed range of selected outcomes (LOS, postoperative complications, discharge to home, hospitalisation cost). We would suggest that this was due to the standardisation of the process of care, even if the knowledge about the mechanisms through which pathways work is insufficient and the evidence determined by meta-analysis is always exploratory in nature and should be considered with caution [47
A strongly significant reduction in the LOS after implementation of the clinical pathway was observed, and even if it can be argued that a general trend towards a continuous reduction of LOS has been existing in actual systems of care (from 1993 to 1999, the mean hospital stay in acute setting/wards for ankle JR dropped from 6.3 to 4.2 days) [48
], this was not observed in the control group. Most of the cohort studies used historical control groups (and therefore potentially susceptible to the bias due to trends in LOS) many authors enrolled consecutive cases in the control groups and this reduced the risk that some cases were missed or excluded, which may have influenced the outcome. Moreover, clinical pathways showed their positive impact on LOS also when applied to other conditions; therefore it is reasonable to think that the reduction of LOS in JR was a consequence of the better organisation of the care when implementing clinical pathways [10
The positive effect of clinical pathways on the organisation of the care was also observed in the other measured outcomes. A possible adverse consequence of an overstretched reduction in LOS could have been an increased rate of postoperative complications, because of the reduction of the level of care. The opposite was found in this meta-analysis. The use of clinical pathways significantly decreased the number of postoperative complications, and this was observed for all the complications including deep venous thrombosis, pulmonary embolism, manipulation, superficial and deep infections and heel decubitus, therefore it is possible to conclude that both reduction of LOS and clinical outcome improvements can be attributed to a better organisation of care.
This can also explain the observed reduction in costs while using clinical pathways. An inappropriate process of care can lead to negative clinical outcomes and to a long LOS. This was avoided in the hospitals using clinical pathways. Unfortunately the majority of the studies included in this meta-analysis reported a reduction of hospitalisation costs without specifying the single costs of the specific elements of the process of care, so it is not possible to conclude that the reduction of the costs was achieved by a more appropriate process of care or simply by a generic reduction of the stay. The rate of patients discharged to home was not significantly increased by the use of clinical pathways and this is a possible weakness of the findings.
This meta-analysis has some further limitations. Most of the reviewed studies were performed in academic hospitals and some studies used small sample sizes, therefore a patient selection could have occurred. This could reduce the generalisation of the results but not their strength because patients included in the clinical pathways group did not differ from the patients treated with usual care in age, sex and clinical co-morbidities. Moreover, from a methodological perspective, when evaluating aggregate results, it is easy to forget that most of the included studies were not randomised trials [49
]. Despite this, if only one RCT was included in the meta-analysis, the analysed cohort studies showed high quality scores and this helped to ensure the internal validity of the research. The majority of the included studies were performed at single sites, so therefore the same staff could have treated both cases and controls with a possible contamination bias. Adopting part of the pathways in usual care if pathways are effective could simply lead to a reduction of the effects of pathways that in this study remain strongly significant.
As has been reported, the funnel plots showed a relatively symmetric distribution, but the point cloud did not have a distinctive funnel form. This was probably due to the relatively high heterogeneity and to the small number of the primary studies included in the meta-analysis. Therefore a publication bias may have also occurred. This risk is implicit in all meta-analyses or review studies because it is easy to understand that original studies that show no benefit or worse outcome when comparing a new technique with usual care are less likely to be published [47
]. Two of the included studies [34
] reported the effects of the clinical pathway together with other hip/knee implant standardisation programmes, and Dowsey et al
] used pathways in association with a pre-admission information seminar for the patients, which could have further increased the statistical heterogeneity of the results. A random effects analysis was performed in order to control this heterogeneity and to increase the strength of the observed findings [51
The purpose of this study was to give a global vision of the impact of hospital clinical pathways for JR. Some limitations are raised from the nature of clinical pathways that are complex interventions in which is difficult to determine which active components are the determinants of the observed effects [20
]. Only a few studies reported on how the clinical pathways were implemented and used at each site, so it is possible that some of the included studies were evaluating different active components with different effects. Moreover, from a health-service research perspective, hospitals are not static environments in which clinical pathways are simply developed and applied but the implementation of clinical pathways is often concurrent with other organisational initiatives that could interact with pathways, enhancing or reducing their effects. It should also be noted that the resources consumed for the development and implementation of clinical pathways were not included in the costs analysis of the studies included in the meta-analysis and this could be a critical issue when applying clinical pathways to low volume hospitals [47