Reacción a "Substituting physicians for nurses in hospital interventions does not affect patient safety, says review"

In general terms, the methodological basis is solid, for several reasons:

• It is a Cochrane systematic review, which implies rigorous methodology, exhaustive searching, and critical assessment of risk of bias.
• It includes 82 randomised clinical trials (RCTs) with more than 28,000 patients in 20 countries.
• RCTs are the gold standard for comparing interventions.
• It assesses clinically relevant outcomes: mortality, adverse events, quality of life, self-efficacy, and satisfaction.

However, there are aspects that require cautious interpretation:

• Significant heterogeneity:
• Different types of nurses (APNs, CNSs, registered nurses).
• Different levels of autonomy and supervision.
• Different medical specialities.
• Different organisational models.
• Variability in the measurement of outcomes.
• Limited and inconsistent economic evidence.
• Predominance of high-income countries (39% United Kingdom).

The methodological conclusion is that the evidence is robust but heterogeneous. The results are reliable at a global level, although they cannot always be extrapolated uniformly to each context.

The results are consistent with previous studies showing that:

• Advanced practice nurses (APN) can manage chronic conditions with similar outcomes to doctors.
• In primary care, safety in the management of mild conditions and follow-up of chronic conditions had already been demonstrated.
• Previous studies also reported good patient satisfaction.

Therefore, it does not contradict previous evidence, but rather reinforces it.

In terms of new developments, this study:

• Focuses specifically on substitution in hospital settings and specialised outpatient clinics, not just in primary care.
• Extends the evidence to multiple specialties (oncology, diabetes, cardiology, dermatology, gynaecology, etc.).
• Identifies areas where nursing care could be even superior (diabetes control, oncology follow-up).
• Clearly points out that substitution is not a simple “one-for-one” replacement, but depends on the organisational model.
• The main novelty [consists of] broad and cross-cutting evidence that consolidates the role of advanced nursing in specialised hospital settings as well.

[In terms of limitations:]

1. Structural heterogeneity: There is no single “replacement” model. Results may depend on training level, protocolisation, actual autonomy, medical supervision and healthcare system organisation.
2. Limited generalisation: Most studies were conducted in the United Kingdom, with little representation from countries with different healthcare systems and little evidence from low- and middle-income countries.
3. Unclear costs and inconsistent economic results. Some studies show savings, others show higher costs due to longer consultation times, more referrals and differences in prescribing.
4. Possible implementation bias. In some cases, nurses offered more time per patient, additional education, and more frequent follow-up. Therefore, the better results could be due not only to the professional category, but also to the more intensive care model.

[The relevance to clinical practice in Spain is] very high, especially in the current context.