PDI
september 2014 - Vol. 34, No. 6 correspondence
To our knowledge, this is the first published case of PD associated with Moraxella non liquefaciens. Several cases with other strains of Moraxella have been described, including M. catarrhalis and M. phenylpyruvica (Table 1). J.M.G. Fandos1* M.B. Mañez2 Nephrology Unit,1 and Microbiology Unit,2 University Hospital Of The Ribera, Alzira, Spain
12. Contreras MR, Ash SR, Swick SD, Grutzner J. Peritonitis due to Moraxella (branhamella) catarrhalis in a diabetic patient receiving peritoneal dialysis. South Med J 1996; 86(5):589–90. 13. Mac Arthur RD. Branhamella catarrhalis peritonitis in two continuous ambulatory peritoneal dialysis patients. Perit Dial Int 1990; 10(2):169–71. doi: 10.3747/pdi.2013-00148
Response Letter to Dr. Wallace – Travel Distance and Home Dialysis Rates in the United States
References 1. Gould IM, Casewell MW. The laboratory diagnosis of peritonitis during continuous ambulatory peritoneal dialysis. J Hosp Infect 1986; 7(2):155–60. 2. Graham DR, Band JD, Thornsberry C, Hollis DG, Weaver RE. Infections caused by Moraxella, Moraxella urethralis, Moraxella-like groups M-5 and M-6, and Kingella kingae in the United States, 1953-1980. Rev Infec Dis 1990; 12:423–31. 3. Rafiq I, Parthasarathy H, Tremlett C, Freeman LJ, Mullin M. Infective endocarditis caused by Moraxella nonliquefaciens in a percutaneous aortic valve replacement. Cardiovasc Revas Med 2011; 12(3):184–6. 4. Johnson DW, Lum G, Nimmo G, Hawley CM. Moraxella nonliquefaciens septic arthritis in a patient undergoing hemodialysis. Clin Infect Dis 1995; 21(4):1039–40. 5. Sudar JM, Alleman MJ, Jonkers GJ, de Groot R, Jongejan C. Acute thyroiditis caused by Moraxella nonliquefaciens. Neth J Med 1994; 45(4):170–3. 6. Schmidt ME, Smith MA, Levy CS. Endophthalmitis caused by unusual gram-negative bacilli: three case reports and review. Clin Infect Dis 1993; 17(4):686–90. 7. Sherman MD, York M, Irvine AR, Langer P, Cevallos V, Whitcher JP. Endophthalmitis caused by beta-lactamasepositive Moraxella nonliquefaciens. Am J Ophthalmol 1993; 115(5):674–6. 8. Rosett W, Heck DM, Hodges GR. Pneumonitis and pul monary abscess associated with Moraxella nonliquefaciens. Chest 1976; 70(5):664–5. 9. Brorson JE, Falsen E, Nilsson-Ehle H, Rödjer S, Westin J. Septicemia due to Moraxella nonliquefaciens in a patient with multiple myeloma. Scand J Infect Dis 1983; 15(2):221–3. 10. Cirillo P, Melfitano A, Pepe V, Delli Carri P, Gesualdo L. Peritonitis due to Moraxella phenylpyruvica. Perit Dial Int 2009; 29(3):358–9. 11. Velusamy L, Mohanty MJ. Moraxella and Kluivera peritonitis in a CAPD patient with human immunodeficiency virus. Perit Dial Int 2003; 23(6):611–2.
Dear Dr. Wallace, Thank you for your thoughts and comments on our paper “Travel distance and home dialysis rates in the United States”. With regards to the designation of home dialysis units, our data came from the end-stage renal disease (ESRD) networks directly and not from the USRDS database. As such, we were able to request more specific detail for this study. Each facility designated as a home dialysis facility had at least 1 patient there on a home dialysis modality (either peritoneal dialysis (PD) or home hemodialysis (HHD)) and this was confirmed with ESRD network 10, where the data was compiled. With regards to the distances presented in the paper, we ran 2 separate analyses for the paper (not mentioned in the abstract because of space limits) – 1 with all patients in the study (177,606) and 1 with only the patients who dialyzed at units with both in-center hemodialysis (IHD) and a home dialysis modalities (PD, HHD or both). The adjusted analyses contained many factors that were felt to potentially influence modality utilization in addition to travel distance. It was felt by our reviewers that the patients attending facilities without home dialysis options may not truly have a choice of modality, hence we limited the sample to patients attending facilities with both IHD and home modalities. When all 177,606 patients were included in the distance calculations, the median travel distances to patients’ initial dialysis facilities were 5.7 miles, 12.6 miles, and 17.8 miles, respectively for IHD, PD, and HHD patients, respectively (Table 1). Comparatively, these respective distances for the group attending facilities with home dialysis and IHD options were 5.4 miles, 3.5 miles, and 6.5 miles, respectively (Table 1). Although the median distances are similar, the mean distances indicate that the limited sample patients may live further from IHD facilities, but closer to home dialysis facilities and also traveled farther to their initial facilities. For the overall sample (177,606 patients), the
This single copy is for your personal, non-commercial use only. For permission to reprint multiple copies or to order presentation-ready copies for distribution, contact Multimed Inc. at [email protected]
675
Downloaded from http://www.pdiconnect.com/ at WASHINGTON UNIVERSITY on November 20, 2015
*email: [email protected]
september 2014 - Vol. 34, No. 6
CORRESPONDENCE
PDI
Table 1 Distances to Initial and Closest Facilities for Limited Sample and Excluded Patients
Group
N
Distance category
Mean
Median
Excluded Patients 78,998
Initial facility Closest home facility Closest IHD facility
13.6 miles 10.5 miles 4.9 miles
5.5 miles 4.9 miles 2.5 miles
Limited Sample 98,608
Initial facility Closest home facility Closest IHD facility
17.2 miles 6.7 miles 5.4 miles
6.6 miles 3.5 miles 2.8 miles
IHD = in-center hemodialysis.
676
the registry may be more influential to modality utilization and better studied using other methods. Our study provided an initial estimate of travel distances for each modality and further examination of this is warranted, especially in rural areas. The limited sample had similar percentages of patients in rural, micropolitan and metropolitan areas as the overall sample. Some of the differences shown in Table 1 of the original article that are statistically significant may not necessarily be clinically significant. For example, although the numbers in Table 1 of the original paper are significant, there likely is not a clinical difference between 2.1 and 2.2% rural population. For the overall sample (refers to 177,606 patients), 152,933 (86.6%) resided in metropolitan areas, 19,555 (11%) in micropolitan areas, and 3706 (2.2%) in rural areas. Hence, as stated in the original paper, we cannot assume these results are reflective of rural areas which, due to the study limitations, we were not able to assess in more detail. We agree with Dr. Wallace that travel distances and distribution of dialysis options should be more specifically examined in rural areas. Yours Sincerely, Suma Prakash MD, MSc, FRCPC DISCLOSURES
The analysis upon which this publication is based were performed under Contract Number ESRD Network 9, contract number HHSM-500-2010-NW009C entitled End Stage Renal Disease Networks Organization for the States of California, Arizona, New Mexico, Colorado, Utah, Pennsylvania, Delaware, Hawaii, Illinois, Kentucky, Ohio and Indiana, sponsored by the Centers for Medicare & Medicaid Services, Department of Health and Human Services. The content of this publication does not necessarily reflect the views or policies of the Department of
This single copy is for your personal, non-commercial use only. For permission to reprint multiple copies or to order presentation-ready copies for distribution, contact Multimed Inc. at [email protected]
Downloaded from http://www.pdiconnect.com/ at WASHINGTON UNIVERSITY on November 20, 2015
distances to initial, closest home and IHD facilities were 2.7, 4.0, and 6.1 miles, respectively. The main concern is that limiting the sample may have influenced our results. Travel distance may have a varying effect on modality choice. We therefore present the adjusted analyses for predictors of PD and HHD utilization in the overall sample of 177,606 patients in the supplemental Tables 2 and 3, respectively. Patients with an increased distance to closest in-center dialysis facility were more likely to utilize PD. Although the distance to closest home dialysis facility significantly impacted PD utilization in the limited sample, this was not the case for the overall sample. The main difference between the limited and overall sample results for PD utilization was that the former group contained the vast majority of the home dialysis patients and there were very few home dialysis patients in the group attending facilities without home modalities (by default). For HHD utilization, the limited sample showed higher HHD use in patients living further from home dialysis facilities and less use of HHD with increased distance to an in-center dialysis facility. However, in the overall analyses, distance was not a significant predictor of HHD utilization, though there was a trend towards less use of HHD with increased distance to a home dialysis facility. As mentioned in the original paper, the main limitation for HHD was that we could not separate the facilities offering PD vs HHD vs both. This would have allowed us to get a more accurate estimate of travel distances for HHD patients. We were not able to separate the percentage of facilities offering PD vs HHD and we suspect, given travel distances, that fewer facilities offer PD than IHD and still fewer offer HHD than PD. However, this might be looked at in future studies. A registry study may not be the most optimal way to determine the relationships between dialysis modality utilization and travel distance. Several issues, such as wanting to dialyze at a facility where one’s nephrologist works, that are not captured in
PDI
september 2014 - Vol. 34, No. 6 correspondence
Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government. The authors assume full responsibility for the accuracy and completeness of the ideas presented. This article is a direct result of the Health Care Quality Improvement Program initiated by the Centers for Medicare & Medicaid Services, which has encouraged identification of quality improvement projects derived from analysis of patterns of care, and therefore required no special funding on the part of this contractor.
Department of Medicine, Division of Nephrology,1 MetroHealth Medical Center2 Case Western Reserve University Ohio, USA *email: [email protected], [email protected] Supplemental material available at www.pdiconnect.com doi: 10.3747/pdi.2014-00168
Is a Home Dialysis Unit Really Just Around the Corner in the United States? Editor: I am writing in response to Prakash et al.’s publication “Travel Distance and Home Dialysis Rates in the United States” in the February 2014 issue of the journal. This topic is of utmost importance to medical legislation and to the future of provision of home dialysis in the United States. Some conclusions from the study are difficult to comprehend for a physician in dialysis network 8 (Alabama, Mississippi, and Tennessee) where home dialysis units are not within 3.5 miles of most of our patients. First, in this study, the median travel distance to the closest facility with home dialysis was less, not more, than to that of the closest in-center hemodialysis unit (IHD) facility, and second, over 55% of dialysis units offered home therapies. In dialysis network 8, only 33% of dialysis units offer home therapies, and because of this and the more rural population, the travel distance to a
DISCLOSURES
The author has no financial conflicts of interest to declare. E. Wallace University of Alabama at Birmingham Birmingham, Alabama, USA email: [email protected]
This single copy is for your personal, non-commercial use only. For permission to reprint multiple copies or to order presentation-ready copies for distribution, contact Multimed Inc. at [email protected]
doi: 10.3747/pdi.2014-00167
677
Downloaded from http://www.pdiconnect.com/ at WASHINGTON UNIVERSITY on November 20, 2015
S. Prakash1,2* S.A. Lewis1,2 A.R. Sehgal1,2
home unit far exceeds that of going to the closest IHD unit. One possibility for the discrepancy is that there is far less access to home dialysis in the more rural southeastern United States. However, another possibility may be with how units were designated as a “home dialysis unit” in this study. Within the United States Renal Data System’s data collection tool CROWNWeb, a unit can be designated as a home unit if it is certified to either offer home dialysis support, take transient patients, or train patients. Should these criteria have been used as opposed to a more restrictive definition, for example including only units with a patient census of at least one, a far higher number of home dialysis units would have been identified as home dialysis units than were actually providing care to patients on home dialysis. If this is the case, it could explain the very large discrepancy between the median distance traveled to the closest home dialysis unit vs the median distance traveled to the initial home dialysis unit. I would kindly ask the authors for clarification on the criteria used to designate a unit as a home dialysis unit for the study. It must be stressed that the results are not representative of many less metropolitan areas of the United States and that the authors rightly state that the results were driven by the 85% of patients living in metropolitan areas. This was aggravated by the fact that the authors excluded census tracts with less than 11 patients due to confidentiality and patients living at great distances from their home dialysis unit, due to skewing of the distance to the closest dialysis unit by a small number of patients, thus excluding the patients most prone to geographic barriers to home dialysis. Studies looking specifically at provision of home dialysis in more rural areas must be undertaken to guide legislation which aims to overcome geographic barriers to improve access to home dialysis care in less metro politan areas.
september 2014 - Vol. 34, No. 6 correspondence
To our knowledge, this is the first published case of PD associated with Moraxella non liquefaciens. Several cases with other strains of Moraxella have been described, including M. catarrhalis and M. phenylpyruvica (Table 1). J.M.G. Fandos1* M.B. Mañez2 Nephrology Unit,1 and Microbiology Unit,2 University Hospital Of The Ribera, Alzira, Spain
12. Contreras MR, Ash SR, Swick SD, Grutzner J. Peritonitis due to Moraxella (branhamella) catarrhalis in a diabetic patient receiving peritoneal dialysis. South Med J 1996; 86(5):589–90. 13. Mac Arthur RD. Branhamella catarrhalis peritonitis in two continuous ambulatory peritoneal dialysis patients. Perit Dial Int 1990; 10(2):169–71. doi: 10.3747/pdi.2013-00148
Response Letter to Dr. Wallace – Travel Distance and Home Dialysis Rates in the United States
References 1. Gould IM, Casewell MW. The laboratory diagnosis of peritonitis during continuous ambulatory peritoneal dialysis. J Hosp Infect 1986; 7(2):155–60. 2. Graham DR, Band JD, Thornsberry C, Hollis DG, Weaver RE. Infections caused by Moraxella, Moraxella urethralis, Moraxella-like groups M-5 and M-6, and Kingella kingae in the United States, 1953-1980. Rev Infec Dis 1990; 12:423–31. 3. Rafiq I, Parthasarathy H, Tremlett C, Freeman LJ, Mullin M. Infective endocarditis caused by Moraxella nonliquefaciens in a percutaneous aortic valve replacement. Cardiovasc Revas Med 2011; 12(3):184–6. 4. Johnson DW, Lum G, Nimmo G, Hawley CM. Moraxella nonliquefaciens septic arthritis in a patient undergoing hemodialysis. Clin Infect Dis 1995; 21(4):1039–40. 5. Sudar JM, Alleman MJ, Jonkers GJ, de Groot R, Jongejan C. Acute thyroiditis caused by Moraxella nonliquefaciens. Neth J Med 1994; 45(4):170–3. 6. Schmidt ME, Smith MA, Levy CS. Endophthalmitis caused by unusual gram-negative bacilli: three case reports and review. Clin Infect Dis 1993; 17(4):686–90. 7. Sherman MD, York M, Irvine AR, Langer P, Cevallos V, Whitcher JP. Endophthalmitis caused by beta-lactamasepositive Moraxella nonliquefaciens. Am J Ophthalmol 1993; 115(5):674–6. 8. Rosett W, Heck DM, Hodges GR. Pneumonitis and pul monary abscess associated with Moraxella nonliquefaciens. Chest 1976; 70(5):664–5. 9. Brorson JE, Falsen E, Nilsson-Ehle H, Rödjer S, Westin J. Septicemia due to Moraxella nonliquefaciens in a patient with multiple myeloma. Scand J Infect Dis 1983; 15(2):221–3. 10. Cirillo P, Melfitano A, Pepe V, Delli Carri P, Gesualdo L. Peritonitis due to Moraxella phenylpyruvica. Perit Dial Int 2009; 29(3):358–9. 11. Velusamy L, Mohanty MJ. Moraxella and Kluivera peritonitis in a CAPD patient with human immunodeficiency virus. Perit Dial Int 2003; 23(6):611–2.
Dear Dr. Wallace, Thank you for your thoughts and comments on our paper “Travel distance and home dialysis rates in the United States”. With regards to the designation of home dialysis units, our data came from the end-stage renal disease (ESRD) networks directly and not from the USRDS database. As such, we were able to request more specific detail for this study. Each facility designated as a home dialysis facility had at least 1 patient there on a home dialysis modality (either peritoneal dialysis (PD) or home hemodialysis (HHD)) and this was confirmed with ESRD network 10, where the data was compiled. With regards to the distances presented in the paper, we ran 2 separate analyses for the paper (not mentioned in the abstract because of space limits) – 1 with all patients in the study (177,606) and 1 with only the patients who dialyzed at units with both in-center hemodialysis (IHD) and a home dialysis modalities (PD, HHD or both). The adjusted analyses contained many factors that were felt to potentially influence modality utilization in addition to travel distance. It was felt by our reviewers that the patients attending facilities without home dialysis options may not truly have a choice of modality, hence we limited the sample to patients attending facilities with both IHD and home modalities. When all 177,606 patients were included in the distance calculations, the median travel distances to patients’ initial dialysis facilities were 5.7 miles, 12.6 miles, and 17.8 miles, respectively for IHD, PD, and HHD patients, respectively (Table 1). Comparatively, these respective distances for the group attending facilities with home dialysis and IHD options were 5.4 miles, 3.5 miles, and 6.5 miles, respectively (Table 1). Although the median distances are similar, the mean distances indicate that the limited sample patients may live further from IHD facilities, but closer to home dialysis facilities and also traveled farther to their initial facilities. For the overall sample (177,606 patients), the
This single copy is for your personal, non-commercial use only. For permission to reprint multiple copies or to order presentation-ready copies for distribution, contact Multimed Inc. at [email protected]
675
Downloaded from http://www.pdiconnect.com/ at WASHINGTON UNIVERSITY on November 20, 2015
*email: [email protected]
september 2014 - Vol. 34, No. 6
CORRESPONDENCE
PDI
Table 1 Distances to Initial and Closest Facilities for Limited Sample and Excluded Patients
Group
N
Distance category
Mean
Median
Excluded Patients 78,998
Initial facility Closest home facility Closest IHD facility
13.6 miles 10.5 miles 4.9 miles
5.5 miles 4.9 miles 2.5 miles
Limited Sample 98,608
Initial facility Closest home facility Closest IHD facility
17.2 miles 6.7 miles 5.4 miles
6.6 miles 3.5 miles 2.8 miles
IHD = in-center hemodialysis.
676
the registry may be more influential to modality utilization and better studied using other methods. Our study provided an initial estimate of travel distances for each modality and further examination of this is warranted, especially in rural areas. The limited sample had similar percentages of patients in rural, micropolitan and metropolitan areas as the overall sample. Some of the differences shown in Table 1 of the original article that are statistically significant may not necessarily be clinically significant. For example, although the numbers in Table 1 of the original paper are significant, there likely is not a clinical difference between 2.1 and 2.2% rural population. For the overall sample (refers to 177,606 patients), 152,933 (86.6%) resided in metropolitan areas, 19,555 (11%) in micropolitan areas, and 3706 (2.2%) in rural areas. Hence, as stated in the original paper, we cannot assume these results are reflective of rural areas which, due to the study limitations, we were not able to assess in more detail. We agree with Dr. Wallace that travel distances and distribution of dialysis options should be more specifically examined in rural areas. Yours Sincerely, Suma Prakash MD, MSc, FRCPC DISCLOSURES
The analysis upon which this publication is based were performed under Contract Number ESRD Network 9, contract number HHSM-500-2010-NW009C entitled End Stage Renal Disease Networks Organization for the States of California, Arizona, New Mexico, Colorado, Utah, Pennsylvania, Delaware, Hawaii, Illinois, Kentucky, Ohio and Indiana, sponsored by the Centers for Medicare & Medicaid Services, Department of Health and Human Services. The content of this publication does not necessarily reflect the views or policies of the Department of
This single copy is for your personal, non-commercial use only. For permission to reprint multiple copies or to order presentation-ready copies for distribution, contact Multimed Inc. at [email protected]
Downloaded from http://www.pdiconnect.com/ at WASHINGTON UNIVERSITY on November 20, 2015
distances to initial, closest home and IHD facilities were 2.7, 4.0, and 6.1 miles, respectively. The main concern is that limiting the sample may have influenced our results. Travel distance may have a varying effect on modality choice. We therefore present the adjusted analyses for predictors of PD and HHD utilization in the overall sample of 177,606 patients in the supplemental Tables 2 and 3, respectively. Patients with an increased distance to closest in-center dialysis facility were more likely to utilize PD. Although the distance to closest home dialysis facility significantly impacted PD utilization in the limited sample, this was not the case for the overall sample. The main difference between the limited and overall sample results for PD utilization was that the former group contained the vast majority of the home dialysis patients and there were very few home dialysis patients in the group attending facilities without home modalities (by default). For HHD utilization, the limited sample showed higher HHD use in patients living further from home dialysis facilities and less use of HHD with increased distance to an in-center dialysis facility. However, in the overall analyses, distance was not a significant predictor of HHD utilization, though there was a trend towards less use of HHD with increased distance to a home dialysis facility. As mentioned in the original paper, the main limitation for HHD was that we could not separate the facilities offering PD vs HHD vs both. This would have allowed us to get a more accurate estimate of travel distances for HHD patients. We were not able to separate the percentage of facilities offering PD vs HHD and we suspect, given travel distances, that fewer facilities offer PD than IHD and still fewer offer HHD than PD. However, this might be looked at in future studies. A registry study may not be the most optimal way to determine the relationships between dialysis modality utilization and travel distance. Several issues, such as wanting to dialyze at a facility where one’s nephrologist works, that are not captured in
PDI
september 2014 - Vol. 34, No. 6 correspondence
Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government. The authors assume full responsibility for the accuracy and completeness of the ideas presented. This article is a direct result of the Health Care Quality Improvement Program initiated by the Centers for Medicare & Medicaid Services, which has encouraged identification of quality improvement projects derived from analysis of patterns of care, and therefore required no special funding on the part of this contractor.
Department of Medicine, Division of Nephrology,1 MetroHealth Medical Center2 Case Western Reserve University Ohio, USA *email: [email protected], [email protected] Supplemental material available at www.pdiconnect.com doi: 10.3747/pdi.2014-00168
Is a Home Dialysis Unit Really Just Around the Corner in the United States? Editor: I am writing in response to Prakash et al.’s publication “Travel Distance and Home Dialysis Rates in the United States” in the February 2014 issue of the journal. This topic is of utmost importance to medical legislation and to the future of provision of home dialysis in the United States. Some conclusions from the study are difficult to comprehend for a physician in dialysis network 8 (Alabama, Mississippi, and Tennessee) where home dialysis units are not within 3.5 miles of most of our patients. First, in this study, the median travel distance to the closest facility with home dialysis was less, not more, than to that of the closest in-center hemodialysis unit (IHD) facility, and second, over 55% of dialysis units offered home therapies. In dialysis network 8, only 33% of dialysis units offer home therapies, and because of this and the more rural population, the travel distance to a
DISCLOSURES
The author has no financial conflicts of interest to declare. E. Wallace University of Alabama at Birmingham Birmingham, Alabama, USA email: [email protected]
This single copy is for your personal, non-commercial use only. For permission to reprint multiple copies or to order presentation-ready copies for distribution, contact Multimed Inc. at [email protected]
doi: 10.3747/pdi.2014-00167
677
Downloaded from http://www.pdiconnect.com/ at WASHINGTON UNIVERSITY on November 20, 2015
S. Prakash1,2* S.A. Lewis1,2 A.R. Sehgal1,2
home unit far exceeds that of going to the closest IHD unit. One possibility for the discrepancy is that there is far less access to home dialysis in the more rural southeastern United States. However, another possibility may be with how units were designated as a “home dialysis unit” in this study. Within the United States Renal Data System’s data collection tool CROWNWeb, a unit can be designated as a home unit if it is certified to either offer home dialysis support, take transient patients, or train patients. Should these criteria have been used as opposed to a more restrictive definition, for example including only units with a patient census of at least one, a far higher number of home dialysis units would have been identified as home dialysis units than were actually providing care to patients on home dialysis. If this is the case, it could explain the very large discrepancy between the median distance traveled to the closest home dialysis unit vs the median distance traveled to the initial home dialysis unit. I would kindly ask the authors for clarification on the criteria used to designate a unit as a home dialysis unit for the study. It must be stressed that the results are not representative of many less metropolitan areas of the United States and that the authors rightly state that the results were driven by the 85% of patients living in metropolitan areas. This was aggravated by the fact that the authors excluded census tracts with less than 11 patients due to confidentiality and patients living at great distances from their home dialysis unit, due to skewing of the distance to the closest dialysis unit by a small number of patients, thus excluding the patients most prone to geographic barriers to home dialysis. Studies looking specifically at provision of home dialysis in more rural areas must be undertaken to guide legislation which aims to overcome geographic barriers to improve access to home dialysis care in less metro politan areas.
