Abstract
Further studies are needed to assess associations between healthcare pathways and outcomes of MD subjects.
Keywords
INTRODUCTION
Muscular dystrophy [MD] refers to a group of more than 30 inherited diseases that cause muscle weakness and wasting. All forms of MD are progressive, and most people with MD eventually lose theability to walk. The most severe complication of muscle weakness due to MD is respiratory failure. In France, referral centres in teaching hospitals were created 10 years ago to provide MD patients with treatments and follow-up designed to prevent complications and improve outcomes [1]. To date, few data are available on utilisation of these referral centres by patients with MD.
Acute respiratory failure [RF] is a major cause of death among patients with MD, and its prevention and treatment can serve as a touchstone for assessing the effectiveness of MD care pathways. MD patients who experience RF or other potentially life-threatening complications and who are followed at a referral centre may be admitted either directly to the centre or to a nearby teaching hospital where the intensivists have the skills required to provide appropriate care, in close collaboration with the referral centre. A potentially less favourable situation is admission to a local non-teaching hospital that is not connected to a referral centre and where the physicians may have limited experience with MD. No data are available on the proportions of patients managed via each of these care pathways or on the outcomes of MD patients admitted for RF or other reasons.
Here, we report data from the French nationwide hospital database concerning admissions of MD patients in France and factors associated with mortality, with special emphasis on RF.
MATERIALS AND METHODS
Data for this study were retrieved from the French nationwide hospital database [Programme de M é dicalisation des syst é mes d’information, PMSI] for 2009 and 2010. We included all admissions of subjects with a code of MD [code G71.0, International Classification of Diseases, 10th revision].
For each admission, we collected the following information: type of hospital [teaching or non-teaching], patient age and sex, type of admission [emergency or scheduled], and whether the patient survived to hospital discharge. We also collected the diagnostic and therapeutic procedures recorded for each patient, and we classified the patients into three diagnostic categories: respiratory failure (RF) with invasive ventilation [intubation and/or tracheotomy], RF without invasive ventilation [non-invasive ventilation (NIV) or high-flow oxygen therapy], or no use of respiratory assistance.
We report categorical data as frequencies and percentages and continuous data as means and standard deviations. Fisher’s exact test was used to evaluate associations between categorical variables. We estimated the mortality rates according to type of hospital, type of admission, and diagnostic category, as well as interactions among these three variables. We then tested for differences related to these three variables. All reported p values are two-tailed and Bonferroni corrected, with p values of 0.05 or less indicating statistical significance. All statistical analyses were performed using Stata 12.0 software [StataCorp LP, College Station, TX, USA].
RESULTS
In 2009 and 2010, 7187 admissions of patients with MD were recorded. Mean patient age was 32.9±20.5 years and 73% of patients were males. The distribution among the three diagnostic categories was as follows: 302 [4.2%] admissions for RF requiring invasive ventilation, 924 [12.9%] admissions for RF requiring only NIV or high-flow oxygen therapy, and 5961 [82.9%] admissions requiring no respiratory assistance.
Table 1 reports mortality rates according to type of hospital, type of admission, and diagnostic category [with the two RF groups collapsed into a single group].
In all, 77 patients died while hospitalised, yielding a rate per admission of 77/7187 [1.1%], including 47 with RF requiring invasive [n = 24] or non-invasive [n = 23] assistance. Only 494 [6.9%] admissions occurred on an emergency basis. Emergency admission was significantly associated with a need for invasive or non-invasive respiratory assistance [24.1% vs. 16.5% for scheduled admissions, p < 0.01] and with hospital mortality [5.9% vs. 0.72% for scheduled admissions, p < 0.01].
Most admissions were to teaching hospitals [5913/7187, 82.3%]. Teaching-hospital admission was associated with a higher frequency of RF requiring invasive or non-invasive assistance [18.4% vs. 11.0% in non-teaching hospitals, p < 0.01] and with lower frequencies of emergency admission [3.08% vs. 24.5%, p < 0.01] and in-hospital death [0.71% vs. 2.75%, p < 0.01]. Mortality was lower in teaching than in non-teaching hospitals for scheduled admissions of patients in need for invasive or non-invasive respiratory assistance [2.4% vs. 10.8%, p < 0.03], or with no need for assistance [0.1% vs. 0.8%, p < 0.01]. Mortality was not significantly different between teaching and non-teaching hospitals for emergency admission of patients with or without respiratory assistance requirement.
DISCUSSION
More than one-sixth of admissions of MD patients were to non-teaching hospitals. most of which have no connection with an MD referral centre. Mortality was highest in the subset of emergency admissions for any type of RF, with no significant difference between teaching and non-teaching hospitals. For other subsets, however, mortality was significantly higher in non-teaching hospitals. Thus, our data suggest room for improvement in care pathways for MD patients requiring admission.
The about 10% mortality rate for emergency admissions of patients with respiratory failure is consistent with previous data [2]. The absence of a significant difference in this situation between teaching and non-teaching hospitals may be ascribable to the dissemination in France of detailed guidelines to help non-specialists manage patients with acute complications of rare diseases, including MD [3–5]. A 2007 survey showed that 70% of emergency-department physicians in France sought specific information before managing patients with rare diseases [6]. Our data suggest that emergency departments in non-teaching hospitals may provide appropriate care to patients with complications of MDs. However, the rate of emergency admissions was significantly higher in non-teaching hospitals, and scheduled admissions were associated with significantly higher mortality rates in non-teaching than in teaching hospitals. Together, these observations suggest, in keeping with data from other countries, that many MD patients may not have access to the best possible care [7, 8].
One limitation of our study is that we did not collect differences in patient health status, which may have influenced the risk of in-hospital death. The hospital database does not contain a detailed description of all complications of MD. However, it is unlikely that sicker patients were preferentially directed to non-teaching hospitals for scheduled admissions. We therefore believe our data raise major concerns regarding the care offered to MD patients, and warrant further investigation of patient care pathways. We are now planning a longitudinal cohort study of admissions over several years to assess the potential influence of patient profiles, notably age and cardiac comorbidities, on hospital outcomes.
LIMITS OF STUDY
Unfortunately French nationwide hospital database does not provide the exact causes of admission and the explanatory factors of death. For example, it is possible that patients who were being treated palliatively were admitted locally which resulted in higher mortality rate. However, considering that literature on this area is very scarce, this preliminary information issued of the national data is the first to show mortality in a neuromuscular subpopulation during hospitalization, and underlines the fragility of this population which probably needs a more stringent and specific emergency circuit for the management of acute failures such as respiratory failure. It also underlines the necessity to perform a large multicenter study evaluating the impact of the emergency circuit and the effect of new centers of excellence currently created for the care of NMDs patients on life expectancy. Last but not least, this study underlines the necessity to improve the French nationwide hospital database, which currently is only aimed to evaluate the hospital efficiency i.e. the ratio of cost against benefit of this welfare system.
CONCLUSION
Our study underlines the need to offer specialised treatment to MD patients experiencing complications, especially if complications are experienced during scheduled hospitalisations. They suggest that admission to referral centres may provide the best outcomes. Further studies are needed to assess associations between healthcare pathways and outcomes of MD patients.
CONFLICTS OF INTEREST STATEMENT
The authors have no conflict of interest to report.
Footnotes
ACKNOWLEDGMENTS
The authors thank of the AFM Task Force on Care Pathways for Neuromuscular Inpatients for theirsupport.