In August 2021, the Italian Ministry of Health published the Ministerial Decree to define the "Criteria for the appropriateness concerning the access to hospital rehabilitation admission" (in neurological, respiratory, cardiological, and orthopedic Units), classifying patients by complexity, the severity of disability and the number of ICD-9 discharge codes. The Appropriateness Decree adopted some fundamental criteria used in the United Kingdom for over 10 years (2009) where the Ministry of Health defined 3 levels of specialized rehabilitation based on the different complexity of the patient's needs. Among the scales, the Rehabilitation Complexity Scale (RCS) has been proposed by the British Society of Rehabilitation Medicine (BSRM), clearly oriented to patients with motor disabilities (neurological and orthopedic), of which the RCS-E (i.e. Extended version) is the more up to date.

The Italian Ministry of Health has proposed the application of the RCS scale as a tool for measuring rehabilitation complexity based on the intensity and level of skills required in terms of nursing, medical and therapeutic care.

In this Clinical Study the Investigators intend to 1. test the application of the new RCS scale to rehabilitation admissions in 16 Italian Pulmonary Rehabilitation Units 2. correlate this scale to the most universally used clinical and functional measures evaluated in the respiratory field 3. investigate the responsiveness of the RCS scale at the end of rehabilitation 4. promote an audit to revise the clinical and rehabilitation conditions -described by items of the RCS-E- to get a specific RCS referable to respiratory patients with MDC4.

Background In August 2021, the Italian Ministry of Health published the Ministerial Decree to define the "Criteria for the appropriateness concerning the access to hospital rehabilitation admission" (in neurological, respiratory, cardiologic, and orthopedic Units), classifying patients by complexity, the severity of disability and the number of ICD-9 discharge codes. The Appropriateness Decree adopts some fundamental criteria used in the United Kingdom for over 10 years (2009) where the Ministry of Health has defined 3 levels of specialized rehabilitation based on the different complexity of the patient's needs. Among the possible scales, the Rehabilitation Complexity Scale (RCS) has been proposed by the British Society of Rehabilitation Medicine (BSRM), clearly oriented to patients with motor disabilities (neurological and orthopedic), of which the RCS-E (i.e. Extended version) is the more up to date.

The Italian Ministry of Health has recently proposed the application of the RCS scale as a tool for measuring rehabilitation complexity based on the intensity and level of skills required in terms of nursing, medical and therapeutic care.

In this Clinical Study the Investigators intend to 1. test the application of the new RCS scale to rehabilitation admissions in 16 Italian Pulmonary Rehabilitation Units 2. correlate this scale to the most universally used clinical and functional measures evaluated in the respiratory field 3. investigate the responsiveness of the RCS scale at the end of rehabilitation 4. promote an audit to revise the clinical and rehabilitation conditions -described by items of the RCS-E- to obtain a specific RCS referable to respiratory patients with MDC4.

Methods This is a multicenter observational study. Patients hospitalized in 16 Pulmonary Rehabilitation Units for a period of respiratory rehabilitation, as defined by the latest guidelines of the American Thoracic Society / European Respiratory Society (ATS/ERS), will be considered. Clinical data [Diagnosis at admission, Demographic and anthropometric data, Provenience (home or hospital), Days of hospitalization in the rehabilitation unit], other than tests/evaluations/scales usually administered at the admission and discharge of the rehabilitation process will be collected.

All information will be used to fill in the RCS-E both at admission and discharge.

The Outcome measures are reported in the dedicated section.

The Sample size has been estimated at 400 patients (considering 25 patients with any DRG/center admitted on 2 specific days at each institute).

Summary statistics will be presented as a descriptive analysis of the mean and standard deviation or median and quartiles for continuous variables and as counts with percentages for categorical or dichotomous variables. Patients will be stratified according to the 3 main DRGs (invasive ventilation 566/565, 88 CRF, 87 COPD) and comparisons will be performed by ANOVA test for continuous variables and chi-square test for categorical or dichotomous variables.

Testing for significant differences in the distributions of discrete variables will be performed with the Chi-Square Test and the Student t-Test will be used for the comparison of pre to post-continuous variables (difference between Baseline and Post program).

Correlations between RCS-E and the standard respiratory/disability scales [Barthel Dyspnea Index, Medical Resource Council (MRC), COPD Assessment Test (CAT), and meters covered in the 6 minutes] will be performed by Spearman's test. An inadequate/adequate correlation with respect to the usual measurements will make it possible to define the "applicability/goodness"" of the scale proposed by the Ministry.

For all tests, a p-value <.05 will be considered significant.

Inclusion Criteria:

• all patients hospitalized for Pulmonary Rehabilitation in two dedicated days (core drilling day 1 = 30 January 2023 and core drilling day 2 = 28 February 2023)

Exclusion Criteria:

• none

Patients hospitalized in 16 Pulmonary Rehabilitation Units will be considered. These patients will participate in a pulmonary rehabilitation program, as defined by the latest guidelines of the American Thoracic Society / European Respiratory Society (ATS/ERS).