Abstract
Background
End-stage kidney disease (ESKD), requiring chronic dialysis or kidney transplantation, significantly affects work ability. This study aimed to identify factors associated with employment in ESKD patients at the initiation of dialysis and at the time of kidney transplantation, and to determine if these factors differ from those in a matched reference group from the general population.
Methods
ESKD patients aged 18–65 years who initiated dialysis or underwent kidney transplantation for the first time between 2005 and 2019 were identified via the Danish Nephrological Registry. These patients were matched with three individuals from the general population based on age, sex, and municipality. Socioeconomic data and information on government benefits were also linked. Multiple logistic regression analyses were conducted to identify employment-associated factors.
Results
The study included 4,469 dialysis patients (median age 55 years, 65% males) matched with 13,262 individuals and 2,294 kidney transplantation patients (median age 49 years, 64% males) matched with 6,790 individuals. Employment rates were significantly lower in ESKD patients compared to their matched reference groups: 11.2% versus 61.2% at dialysis initiation, and 19.8% versus 67.4% at transplantation. Male sex and higher education were associated with employment in both patient and reference groups. However, age, ethnicity, education, and the absence of diabetes (in dialysis patients) and ischemic heart disease (in transplant patients) had a stronger association with employment in the reference group. For ESKD patients, peritoneal dialysis, shorter dialysis duration, preemptive transplantation, and absence of comorbidities were positively associated with employment. Ethnic Danish patients were more likely to be employed than immigrants, particularly among transplant recipients.
Conclusions
While male sex, higher education, ethnicity, and the absence of comorbidities were positively associated with employment in both ESKD and reference groups, these factors were less impactful in ESKD patients. ESKD remains a primary driver of unemployment, underscoring the need for early intervention and tailored support to maintain work ability.
Supplementary Information
The online version contains supplementary material available at 10.1186/s12889-026-26897-1.
Keywords: dialysis, kidney transplantation, end-stage kidney disease, ESKD, employment, explanatory factors, cohort study, register study
Background
Employment is important for quality of life, and in many societies, employment is of immense importance to ensure the economy necessary to sustain well-being and to be a part of society [1]. Employment is also important in societies where work is part of the norm and essential for personal identity, social role, and status. Studies have shown that a higher proportion of employed individuals are in good mental health whereas a higher proportion of unemployed individuals experience poor mental health. Therefore, stable employment seems closely associated with good physical and mental health [2]. Conversely, unemployment may be associated with long-standing illness, poorer mental health, psychological distress, more frequent medical consultations, higher hospital admission rates, and even increased mortality [3, 4].
End-stage kidney disease (ESKD) has a major impact on quality of life [5–7], and for many patients, the condition affects their ability to work. Previous studies have reported low employment rates in both dialysis and kidney transplantation patients [8–10]. In a systematic review by our group, the employment rate worldwide was 26% for dialysis patients, 37% for patients who received a kidney transplantation, and 38% post-transplantation [11]. However, these worldwide data are characterized by large variations between studies and countries.
Previous studies have suggested that several factors had a positive impact on employment in ESKD patients [11]. These included younger age, male sex, higher education, being employed at the onset of ESKD, a shorter disease duration, a short duration of dialysis treatment, preemptive kidney transplantation, the possibility of a living kidney donor, and a lack of comorbidities such as diabetes, ischaemic heart diseases, and depression [11]. However, most studies were based on small samples and employment was assessed as self-reported work ability. None of the studies used reference groups for comparison, rendering interpretation of the individual studies challenging. To date, there are no nationwide studies describing factors associated with employment in ESKD patients compared with the general population.
The main purpose of the present study was (1) to identify factors associated with being employed for ESKD patients when chronic dialysis was initiated and at the time of kidney transplantation, and (2) to investigate whether these factors differ between ESKD patients and a reference group from the general population matched for age, sex, and municipality.
Methods
Design
This register-based nationwide cohort study with an age-, sex-, and municipality-matched population investigated factors associated with employment in ESKD patients at the initiation of dialysis or at the time of kidney transplantation between 2005 and 2019. The reporting quality of the study was assessed according to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) cohort checklist [12].
Study population
All patients aged 18–65 years registered in the Danish Nephrological Register (DNR) between 2005 and 2019 who initiated dialysis or received kidney transplantation were included [13].
The DNR contains information on all ESKD patients in Denmark since 1990 and includes comprehensive data on dialysis modalities (hemodialysis or peritoneal dialysis), changes between modalities, and the time of kidney transplantation [13].
The study population was divided into two nonexclusive cohorts: a dialysis cohort and a kidney transplantation cohort. At the time of inclusion (the date of initiation of dialysis or transplantation), each patient was matched with up to three individuals (over 97% of patients) from the general population by year of birth, sex, and most recent known municipality, creating a reference cohort for both the dialysis and the kidney transplantation cohort. To be sure that we had updated information on patients we conditioned on patients living in Denmark for three years prior to their inclusion, whereas members of the reference cohort had to be alive and reside in Denmark at the end of the previous calendar year. Both patients and reference cohort members had to have an entry in the Danish Register for Evaluation of Marginalization (DREAM) [14]. DREAM is a longitudinal database with weekly information on all Danish citizens who have received social transfer payments since 1991 [14]. After 2008, DREAM further includes all Danish citizens with a monthly income from wages.
Some patients entered the DNR with graft loss, preventing their inclusion in the kidney transplantation cohort because of missing data on their first kidney transplantation. However, these patients were eligible for inclusion in the dialysis population. The inclusion or index date was defined as the date of first registered dialysis for the dialysis cohort patients and the date 28 days prior to the date of kidney transplantation for the transplantation cohort patients. The index date of a patient carries over to the individuals of their reference group.
Outcome
The outcome of interest was labour market affiliation at the time of initiation of dialysis or kidney transplantation. Data were obtained from DREAM. Labour market affiliation was categorized as (1) in employment (if the cohort member received no social transfer payments); (2) currently out of the workforce (if the cohort member received social transfer payments related to unemployment or sickness absence); or (3) permanently out of the workforce (if the cohort member had retired or received either public or disability pension). Labour market affiliation was based on the week of the index date. See Additional file 1 for the specific categorization of DREAM codes.
Covariates/characteristics
Information on patient age and sex was obtained from Statistics Denmark (https://www.dst.dk/da/). Age at the end of the index year was categorized into four groups: 18–35, 36–45, 46–55, and 56–66 years. ‘Time period’ concerns the year of the index date. The year was recorded to be within one of three time periods: 2005–2009, 2010–2014, and 2015–2019. Ethnicity was dichotomized as immigrated or Danish and was based on information from Statistics Denmark. Data on the highest attained educational level were retrieved from the Danish Education Register and categorized as (1) primary school; (2) vocational training; (3) college graduate; and (4) university degree [15].
Comorbidities were assessed via recorded diagnoses 5 years prior to the index date from the Danish National Patient Register [16], which is based on the International Classification of Diseases, Tenth Revision (ICD-10) codes for diabetes (DE10-14) and ischemic heart disease (DI20-25). For patients in the dialysis and transplantation cohorts, information on the cause of ESKD and dialysis modality was obtained from the DNR.
Statistical analysis
Patient and reference cohort characteristics are presented as numbers and percentages across types of labour market affiliation. The associations between labour market affiliation and cohort characteristics were assessed via chi-square tests.
The odds of being employed at the initiation of dialysis or kidney transplantation were modelled via logistic regressions. Odds ratios of covariates association with employment were estimated in both the dialysis and transplantation cohorts. Differences between patients and the matched reference groups in the covariates associations with employment were assessed via an interaction term. Logistic regression models for each of the covariates were adjusted as follows: age was adjusted for sex, and sex was adjusted for age. The time period was adjusted for age and sex. Ethnicity and education were individually adjusted for age, sex, and time period. Comorbidities (diabetes and ischemic heart disease), dialysis modality, and cause of ESKD, and for the transplantation cohort, time on dialysis and waiting time for transplantation were individually adjusted for sex, age, year group, ethnicity, and educational level. The data were analysed via SAS Enterprise Guide version 8.3 Update 7 (8.3.7.202) (64 bit).
Results
Background data
A total of 6,763 ESKD patients were eligible for inclusion in the study, including 4,469 dialysis patients, and 2,294 kidney transplant recipients. We excluded 208 patients who did not reside in Denmark, 114 with graft loss, 132 with missing data in DREAM, and 16 without a match.
The matched reference cohort for dialysis patients included 13,262 individuals, whereas the reference cohort for kidney transplant patients included 6,790 matched individuals. The median age was 55 years for dialysis patients and 49 years for kidney transplant patients. Approximately two-thirds of both ESKD cohorts were male (see Tables 1 and 2). Further details regarding background data and matching can be seen in a previous article by the authors [17].
Table 1.
Employment rates among end-stage kidney disease patients initiating dialysis and a matched reference group
| Dialysis patients | Reference group | |||
|---|---|---|---|---|
| Total | Employed n (%) |
Total | Employed n (%) |
|
| Total | ||||
| N n (%) | 4469 | 502 (11.2) | 13,262 | 8114 (61.2) |
| Age at end of index year | ||||
| P-value# | < 0.0.0001 | < 0.0.0001 | ||
| 18–35 | 512 | 79 (15.4) | 1485 | 883 (59.5) |
| 36–45 | 664 | 79 (11.9) | 1971 | 1533 (77.8) |
| 46–55 | 1162 | 154 (13.3) | 3460 | 2619 (75.7) |
| 56–66 | 2131 | 190 (8.9) | 6346 | 3079 (48.5) |
| Sex | ||||
| P-value# | < 0.0.0001 | < 0.0.0001 | ||
| Male | 2888 | 384 (13.3) | 8567 | 5529 (64.5) |
| Female | 1581 | 118 (7.5) | 4695 | 2585 (55.1) |
| Time period | ||||
| P-value# | 0.0007 | < 0.0.0001 | ||
| 2005–2009 | 1673 | 153 (9.2) | 4978 | 2963 (59.5) |
| 2010–2014 | 1489 | 172 (11.6) | 4410 | 2644 (60.0) |
| 2015–2019 | 1307 | 177 (13.5) | 3874 | 2507 (64.7) |
| Ethnicity | ||||
| P-value# | 0.54 | < 0.0.0001 | ||
| Immigrated | 481 | 50 (10.4) | 1165 | 610 (52.4) |
| Danish | 3988 | 452 (11.3) | 12,097 | 7504 (62.0) |
| Education | ||||
| P-value# | < 0.0.0001 | < 0.0.0001 | ||
| Primary school | 1947 | 164 (8.4) | 4235 | 1981 (46.8) |
| Vocational training | 1651 | 184 (11.1) | 5112 | 3318 (64.9) |
| College graduate | 577 | 100 (17.3) | 2626 | 1828 (69.6) |
| University degree | 160 | 48 (30.0) | 1043 | 871 (83.5) |
| Missing | 134 | 246 | ||
| Diabetes | ||||
| P-value# | < 0.0.0001 | < 0.0.0001 | ||
| Yes | 1622 | 119 (7.3) | 407 | 140 (34.4) |
| No | 2847 | 383 (13.5) | 12,855 | 7974 (62.0) |
| Ischemic heart disease | ||||
| P-value# | < 0.0.0001 | < 0.0.0001 | ||
| Yes | 707 | 41 (5.8) | 394 | 145 (36.8) |
| No | 3762 | 461 (12.3) | 12,868 | 7969 (61.9) |
| Cause of ESKD* | ||||
| P-value# | < 0.0.0001 | |||
| Chronic glomerulonephritis | 473 | 76 (16.1) | ||
| Cystic kidney disease | 282 | 45 (16.0) | ||
| Systemic diseases | 1365 | 100 (7.3) | ||
| Chronic pyelonephritis/nephrolithiasis | 142 | 15 (10.6) | ||
| Interstitial nephropathy | 147 | 10 (6.8) | ||
| Uraemia without specification | 494 | 54 (10.9) | ||
| Hereditary kidney disease | 75 | 8 (10.7) | ||
| Other | 188 | 18 (9.6) | ||
| Missing | 1303 | |||
| Dialysis modality | ||||
| P-value# | < 0.0.0001 | |||
| Hemodialysis | 2893 | 264 (9.1) | ||
| Peritoneal dialysis | 1576 | 238 (15.1) | ||
*ESKD: end-stage kidney disease
#P-values refer to differences within the patient and the reference group, respectively
Table 2.
Employment rates in end-stage kidney disease patients at the time of kidney transplantation and a matched reference group
| Kidney transplantation | Reference group | |||
|---|---|---|---|---|
| Total | Employed n (%) |
Total | Employed n (%) |
|
| Total | ||||
| N n (%) | 2294 | 453 (19.8) | 6790 | 4574 (67.4) |
| Age at end of index year | ||||
| P-value# | 0.03 | < 0.0.0001 | ||
| 18–35 | 446 | 79 (17.7) | 1291 | 791 (61.3) |
| 36–45 | 482 | 84 (17.4) | 1431 | 1139 (79.6) |
| 46–55 | 668 | 157 (23.5) | 1991 | 1527 (76.7) |
| 56–66 | 698 | 133 (19.1) | 2077 | 1117 (53.8) |
| Sex | ||||
| P-value# | < 0.0.0001 | < 0.0001 | ||
| Male | 1464 | 351 (24.0) | 4337 | 3067 (70.7) |
| Female | 830 | 102 (12.3) | 2453 | 1507 (61.4) |
| Time-period | ||||
| P-value# | 0.009 | 0.24 | ||
| 2005–2009 | 645 | 115 (17.8) | 1908 | 1289 (67.6) |
| 2010–2014 | 834 | 149 (17.9) | 2469 | 1634 (66.2) |
| 2015–2019 | 815 | 189 (23.2) | 2413 | 1651 (68.4) |
| Ethnicity | ||||
| P-value# | 0.0008 | < 0.0.0001 | ||
| Immigrated | 266 | 32 (12.0) | 640 | 366 (57.2) |
| Danish | 2028 | 421 (20.8) | 6150 | 4208 (68.4) |
| Education | ||||
| P-value# | < 0.0.0001 | < 0.0.0001 | ||
| Primary school | 882 | 117 (13.3) | 2183 | 1169 (53.6) |
| Vocational training | 856 | 174 (20.3) | 2483 | 1784 (71.9) |
| College graduate | 386 | 97 (25.1) | 1401 | 1036 (74.0) |
| University degree | 114 | 61 (53.5) | 601 | 523 (87.0) |
| Missing | 56 | 122 | ||
| Diabetes | ||||
| P-value# | < 0.0.0001 | < 0.0.0001 | ||
| Yes | 526 | 64 (12.2) | 159 | 60 (37.7) |
| No | 1768 | 389 (22.0) | 6631 | 4514 (68.1) |
| Ischemic heart disease | ||||
| P-value# | 0.003 | < 0.0.0001 | ||
| Yes | 363 | 51 (14.1) | 171 | 78 (45.6) |
| No | 1931 | 402 (20.8) | 6619 | 4496 (67.9) |
| Cause of ESKD* | ||||
| P-value# | 0.0004 | |||
| Chronic glomerulonephritis | 429 | 98 (22.8) | ||
| Cystic kidney disease | 252 | 56 (22.2) | ||
| Systemic diseases | 535 | 68 (12.7) | ||
| Chronic pyelonephritis/nephrolithiasis | 81 | 9 (11.1) | ||
| Interstitial nephropathy | 62 | 8 (12.9) | ||
| Uraemia without specification | 266 | 40 (15.0) | ||
| Hereditary kidney disease | 46 | 11 (23.9) | ||
| Other | 53 | 9 (17.0) | ||
| Missing | 570 | |||
| Dialysis modality | ||||
| P-value# | < 0.0.0001 | |||
| Hemodialysis | 1146 | 126 (11.0) | ||
| Peritoneal dialysis | 656 | 158 (24.1) | ||
| Waiting time for TX§ (months) | ||||
| P-value# | 0.03 | |||
| < 12 | 699 | 139 (19.9) | ||
| 12–24 | 253 | 48 (19.0) | ||
| > 24 | 353 | 47 (13.3) | ||
| Missing | 40 | |||
| Kidney donor type | ||||
| P-value# | 0.01 | |||
| Deceased donor | 1345 | 242 (18.0) | ||
| Living donor | 949 | 211 (22.2) | ||
| Time on dialysis before TX (months) | ||||
| P-value# | < 0.0.0001 | |||
| < 12 | 537 | 114 (21.2) | ||
| 12–24 | 454 | 77 (17.0) | ||
| > 24 | 811 | 93 (11.5) | ||
| Preemptive | 492 | 169 (34.4) | ||
*ESKD: end-stage kidney disease
§TX: transplantation (deceased donor)
# P-values refer to differences within the patient and the reference group, respectively
Characteristics of patients initiating dialysis and the reference group
The characteristics of the dialysis patients and the reference group at the index time are shown in Table 1. In total, 11.2% of the participants were employed when initiating dialysis, whereas 61.2% were employed in the reference group.
Among the dialysis patients, 40.4% were currently out of work and 48.4% were permanently out of the workforce at the time of initiating dialysis, whereas 14.8% were currently out of work and 24.0% were permanently out of the workforce in the reference group (see Additional file 2).
Employment rates differed between age groups for both dialysis patients and the reference group. For dialysis patients, the employment rates were highest in the youngest age group (15.4%) and lowest in the oldest age group (8.9%), whereas in the reference group, the employment rates were highest in the 36–45 years (77.8%) and 46–55 years (75.7%) age groups.
Among dialysis patients initiating dialysis in 2015–2019, the employment rate was 13.5%, which was significantly higher than that for patients in 2005–2009 (9.2%) or 2010–2014 (11.6%). The employment rates across these periods for the reference group were 59.5% (2005–2009), 60.0% (2010–2014), and 64.7% (2015–2019).
The employment rates for dialysis patients were not significantly different among people of Danish ethnicity and those who had immigrated (10.4% vs. 11.3%). Among the reference group, significantly more people of Danish ethnicity were employed (62.0%) than immigrants (52.4%).
A greater proportion of males than females were employed among both dialysis patients (13.3% vs. 7.5%) and the reference group (64.5% vs. 55.1%). Similarly, a greater proportion of both patients and the reference group who had completed more than primary school were employed. Among the dialysis patients, 30% with a university degree were employed, whereas 8.4% with a primary school degree were employed. Among the reference group, 83.5% with a university degree and 46.8% with a primary school degree were employed (Table 1).
Characteristics of kidney transplantation patients and the reference group
The characteristics of the patients and the reference groups at the index time are shown in Table 2. In total, 19.8% of the patients were employed at the time of transplantation compared with 67.4% in the reference group, whereas 39.0% were currently out of work and 41.3% permanently out of the workforce at the time of transplantation compared with 17.5% currently out of work and 15.1% permanently out of the workforce in the reference group (see Additional file 3).
The employment rates for the transplanted patients were highest, 23.5% among those aged 46–55 years, whereas they were 17.7% for the youngest patients aged 18–35 years. For the reference group, the employment rates were highest in the 36–45 years (79.6%) and 46–55 years (76.7%) age groups and lowest in the 56–66 years (53.8%) age group.
A greater proportion of males than females were employed among both transplanted patients (24.0% vs. 12.3%) and the reference group (70.7 vs. 61.4%).
Among patients who underwent transplantation between 2015 and 2019, the employment rate was 23.2%, significantly higher than that for patients who underwent transplantation between 2005 and 2009 (17.8%) or 2010 and 2014 (17.9%). In contrast, the employment rates did not change substantially across these periods for the reference groups 2005–2009 (67.6%), 2010–2014 (66.2%), and 2015–2019 (68.4%).
The employment rate for patients who received a transplant was higher among people of Danish ethnicity (20.8%) than among immigrants (12.0%) and for the reference group (68.4% vs. 57.2%, respectively).
Employment rates varied significantly according to education and were higher among persons with higher educational training levels for both patients and the reference group (Table 2). Among kidney transplant patients, the employment rate was 53.5% if they had a university degree, whereas it was 13.3% among those with only primary school education. Among the reference group, the employment rate was 87.0% if they had a university degree, whereas 53.6% were employed if they had a primary school degree.
Factors associated with employment
Dialysis patients compared with the reference group
Table 3 shows the odds ratio (OR) of being employed for dialysis patients and the reference group and tests for interaction between patients and the reference group in relation to employment.
Table 3.
Odds ratio (OR) with 95% confidence intervals (CI) for employment versus currently out of work (sick leave or unemployed) at the time of initiation dialysis
| Dialysis patients | Reference group | ||
|---|---|---|---|
| OR (CI) | OR (CI) | P-value for interaction# | |
| Age at end of index year1 | N:4469* | N:13,262* | |
| 18–35 | 1 | 1 | < 0.0001 |
| 36–45 | 0.73 (0.52, 1.02) | 2.37 (2.04, 2.75) | |
| 46–55 | 0.82 (0.61, 1.11) | 2.11 (1.85, 2.40) | |
| 56–66 | 0.53 (0.40, 0.70) | 0.63 (0.56, 0.71) | |
| Sex2 | |||
| Male | 1 | 1 | 0.047 |
| Female | 0.52 (0.42, 0.65) | 0.66 (0.61, 0.71) | |
| Time-period3 | |||
| 2005–2009 | 1 | 1 | 0.09 |
| 2010–2014 | 1.28 (1.01, 1.62) | 0.99 (0.91, 1.08) | |
| 2015–2019 | 1.53 (1.21, 1.93) | 1.22 (1.11, 1.33) | |
| Ethnicity4 | |||
| Danish | 1 | 1 | 0.03 |
| Immigrated | 0.85 (0.62, 1.16) | 0.58 (0.51, 0.66) | |
| Education4 | N:4335 | N:13,016 | |
| Primary school | 1 | 1 | 0.002 |
| Vocational training | 1.34 (1.07, 1.68) | 2.13 (1.95, 2.33) | |
| College graduate | 2.30 (1.75, 3.03) | 2.79 (2.51, 3.11) | |
| University degree | 4.93 (3.35, 7.25) | 5.56 (4.65, 6.64) | |
| Diabetes5 | N:4335 | N:13,016 | |
| No | 1 | 1 | 0.04 |
| Yes | 0.55 (0.44, 0.69) | 0.40 (0.32, 0.50) | |
| Ischemic heart disease5 | N:4335 | N:13,016 | |
| No | 1 | 1 | 0.30 |
| Yes | 0.52 (0.37, 0.73) | 0.42 (0.34, 0.53) | |
| Cause of ESKD5 | N:3075 | ||
| Systemic diseases | 1 | ||
| Chronic glomerulonephritis | 2.05 (1.47, 2.86) | ||
| Cystic kidney disease | 2.35 (1.59, 3.48) | ||
| Chronic pyelonephritis/nephrolithiasis | 1.34 (0.73, 2.47) | ||
| Interstitial nephropathy | 0.94 (0.47, 1.86) | ||
| Uraemia without specification | 1.50 (1.04, 2.14) | ||
| Hereditary kidney disease | 1.19 (0.54, 2.62) | ||
| Other | 1.36 (0.79, 2.33) | ||
| Dialysis modality 5 | N:4335 | ||
| Hemodialysis | 1 | ||
| Peritoneal dialysis | 1.69 (1.39, 2.05) | ||
1adjusted for sex; 2adjusted for age; 3adjusted for age and sex; 4adjusted for age, sex, and time period; 5adjusted for age, sex, time period, ethnicity, and education
*N changes due to exclusion of observations categorized as missing, this first N persists for the population where N is not directly specified
#P-value for interaction denotes test for different associations with employment between patients and reference group for each characteristic
There was a variation in the odds of being employed between the different age groups for both the dialysis patients and the reference group, and the association between employment and age group was significantly different for the dialysis patients and for the reference group (pinteraction <0.0001). For both dialysis patients and the reference group, an age of 56–66 years was associated with lower odds of employment (OR 0.53, 95% CI 0.40, 0.70 and OR 0.63, 95% CI 0.56, 0.71, respectively) compared with an age of 18–35 years. The odds of employment for dialysis patients aged 36–45 years (OR 0.73, 95% CI 0.53,1.02) and 46–55 years (OR 0.82, 95% CI 0.61, 1.11) did not differ significantly from those in the group aged 18–35 years, whereas the reference group had higher odds of being employed if they were 36–45 years (OR 2.37, 95% CI 2.04, 2.75) or 46–55 years (OR 2.11, 95% CI 1.85, 2.40) than if they were 18–35 years.
Among both dialysis patients and the reference group, women had lower odds of being employed than men (OR 0.52, 95% CI 0.42, 0.65 vs. OR 0.66, 95% CI 0.61, 0.71, respectively). The association was more pronounced among the dialysis patients than in the reference group (pinteraction <0.05).
Both dialysis patients and the reference group were more likely to be employed if they had higher educational training than if they had primary schooling, Table 3. The association was more pronounced among the reference group than in the dialysis group (pinteraction <0.01).
Among dialysis patients, immigrants had lower odds of being employed than those of Danish ethnicity (OR 0.85, 95% CI 0.62, 1.16). This association persisted in the reference group as well (OR 0.58, 95% CI, 95% CI 0.51, 0.66). However, the difference between immigrants and those of Danish ethnicity was more pronounced in the reference group than in the dialysis group (pinteraction = 0.02) (Table 3).
The odds of being employed were increasing over the three time periods both in the dialysis group and in the reference group, but the increase was not significantly different among the dialysis patients and the reference group (pinteraction = 0.09) (Table 3).
Patients with comorbidities such as diabetes or ischemic heart disease had lower odds of being employed with OR 0.55, 95% CI 0.44, 0.69 (diabetes) and OR 0.52, 95% CI 0.37, 0.73 (ischemic heart disease) for dialysis patients, with OR 0.40, 95% CI 0.32, 0.05 (diabetes) and 0.42, 95% CI 0.34, 0.53 (ischemic heart disease) for the reference group The difference was more pronounced for the reference group than for dialysis patients in relation to diabetes, but not for ischemic heart disease (pinteraction = 0.04 for diabetes and 0.30 for ischemic heart disease), respectively. (Table 3).
Patients who initiated peritoneal dialysis had greater odds of being employed (OR 1.70, 95% CI 1.39, 2.05) than patients who initiated hemodialysis.
The cause of ESKD also affected the odds of being employed, with higher odds in patients with cystic kidney disease and chronic glomerulonephritis (OR 2.35, 95% CI 1.59, 3.48 and OR 2.05, 95% CI 1.47, 2.86, respectively) than in those with systemic diseases (Table 3).
Kidney transplantation patients compared with the reference group
Table 4 shows OR for employment and tests for interaction between the transplanted patients and the reference group.
Table 4.
Odds ratio (OR) with 95% confidence intervals (CI) for employment at time of kidney transplantation
| Kidney transplantation | Reference group | ||
|---|---|---|---|
| OR (CI) | OR (CI) | P-value interaction# | |
| Age at end of index year 1 | N:2294* | N:6790* | |
| 18–35 | 1 | 1 | < 0.0001 |
| 36–45 | 1.00 (0.71, 1.40) | 2.55 (2.15, 3.03) | |
| 46–55 | 1.44 (1.07, 1.95) | 2.12 (1.82, 2.47) | |
| 56–66 | 1.12 (0.82, 1.53) | 0.75 (0.65, 0.87) | |
| Sex2 | |||
| Male | 1 | 1 | 0.003 |
| Female | 0.44 (0.34, 0.56) | 0.65 (0.59, 0.73) | |
| Time period3 | |||
| 2005–2009 | 1 | 1 | 0.10 |
| 2010–2014 | 1.01 (0.77, 1.32) | 0.95 (0.83, 1.08) | |
| 2015–2019 | 1.38 (1.06, 1.80) | 1.03 (0.90, 1.18) | |
| Ethnicity4 | |||
| Danish | 1 | 1 | 0.71 |
| Immigrated | 0.51 (0.34, 0.75) | 0.55 (0.46, 0.65) | |
| Education4 | N: 2238 | N:6668 | |
| Primary school | 1 | 1 | 0.03 |
| Vocational training | 1.61 (1.24, 2.09) | 2.20 (1.94, 2.49) | |
| College graduate | 2.29 (1.68, 3.11) | 2.59 (2.23, 3.01) | |
| University degree | 7.83 (5.11, 12.0) | 5.55 (4.29, 7.17) | |
| Diabetes5 | N: 2238 | N:6668 | |
| No | 1 | 1 | 0.13 |
| Yes | 0.45 (0.33, 0.60) | 0.31 (0.22, 0.44) | |
| Ischemic heart disease5 | N: 2238 | N:6668 | |
| No | 1 | 1 | |
| Yes | 0.67 (0.48, 0.94) | 0.41 (0.30, 0.57) | 0.04 |
| Cause of ESKD5 | N: 1680 | ||
| Systemic disease | 1 | ||
| Chronic glomerulonephritis | 1.96 (1.37, 2.80) | ||
| Cystic kidney disease | 2.12 (1.40, 3.20) | ||
| Chronic pyelonephritis/nephrolithiasis | 0.99 (0.46, 2.13) | ||
| Interstitial nephropathy | 1.05 (0.46, 2.36) | ||
| Uraemia without specification | 1.37 (0.88, 2.14) | ||
| Hereditary kidney disease | 2.06 (0.96, 4.40) | ||
| Other | 1.61 (0.73, 3.58) | ||
| Dialysis modality5 | N: 1754 | ||
| Hemodialysis | 1 | ||
| Peritoneal dialysis | 2.77 (2.10, 3.65) | ||
| Waiting time for TX (months)5 | N: 1268 | ||
| < 12 | 1 | ||
| 12–24 | 0.91 (0.62, 1.34) | ||
| > 24 | 0.69 (0.47, 1.01) | ||
| Kidney donor type5 | 5) N: 2238 | ||
| Deceased donor | 1 | ||
| Living donor | 1.20 (0.96, 1.51) | ||
| Time on dialysis (months)5 | N: 2238 | ||
| < 12 | 1 | ||
| 12–24 | 0.79 (0.56, 1.10) | ||
| > 24 | 0.51 (0.37, 0.71) | ||
| Preemptive | 1.88 (1.40, 2.52) | ||
1adjusted for sex; 2adjusted for age; 3adjusted for age and sex; 4adjusted for age, sex, and time period; 5adjusted for age, sex, time period, ethnicity, and education
*N changes due to exclusion of observations categorized as missing, this first N persists for the population where N is not directly specified
#P-value for interaction denotes test for different associations with employment between patients and reference group for each characteristic
The associations between employment and age were significantly different for transplantation patients compared with the reference group (pinteraction <0.0001). Age had less influence on employment among transplanted patients than in the reference group.
Women had lower odds of being employed than men among both transplanted patients (OR 0.44, 95% CI 0.34, 0.56) and the reference group (OR 0.65, 95% CI 0.59, 0.73). The association was stronger among patients than among the reference group (pinteraction =0.003) (Table 4).
Both transplanted patients and the reference group had higher OR of being employed if they had higher educational training than if they had primary schooling. The association was more pronounced among the reference group than among the transplanted patients (pinteraction <0.05). (Table 4).
Those who immigrated had lower odds of being employed compared with people of Danish ethnicity among both transplanted patients (OR 0.51, 95% CI 0.34, 0.75) and the reference group (OR 0.55, 95% CI 0.46, 0.65), without significant difference between the transplanted patients and the reference group (pinteraction = 0.71) (Table 4).
The odds of being employed at index time were higher in 2015–2019 (OR 1.38, 95% CI 1.06, 1. 80) than in 2005–2009 for transplantation patients, whereas the odds did not vary between time periods for the reference group. However, there was no significant difference between the time periods for the patients and the reference group (pinteraction = 0.10) (Table 4).
Patients initiating peritoneal dialysis were more likely to be employed (OR 2.77, 95% CI 2.10, 3.65) than patients initiating hemodialysis. The OR of being employed was lower for those who had been on dialysis for 12–24 months (OR 0.79, 95% CI 0.56, 1.10) and > 24 months (OR 0.51, 95% CI 0.37, 0.71) than for those who have been on dialysis less than 12 months. Patients who had not been on dialysis (pre-emptive) had higher odds of being employed compared with dialysis patients (OR 1.88, 95% CI 1.40, 2.52).
In this study, we found no strong association between the donor type (deceased versus living donor) and the employment rate.
Patients and the reference group with comorbidities such as diabetes or ischaemic heart disease had lower odds of being employed (OR 0.45, 95% CI 0.33, 0.60 vs. OR 0.31, 95% CI 0.22, 0.44) for diabetes and for ischemic heart disease (OR 0.67, 95% CI 0.48, 0.94 vs. OR 0.41, 95% CI 0.30, 0.57), and those in the reference group had even lower odds than those in the transplantation group in relation to ischaemic heart disease (pinteraction =0.04) (Table 4).
The cause of kidney disease also influenced employment, and there were greater odds of being employed among patients with cystic kidney disease (OR 2.12, 95% CI 1.40, 3.20) and chronic glomerulonephritis (OR 1.96, 95% CI 1.37, 2.81) than among those with systemic disease.
Discussion
This is the first nationwide study investigating factors associated with employment at the time of initiating dialysis and kidney transplantation and comparing the results to those of a reference group from the general population. Our main findings were that male sex, higher education, and the absence of comorbidities were all positively associated with being employed in both ESKD patients and the reference groups. However, there were significant interactions, meaning that factors like age, ethnicity, education, and comorbidities were less important for the ability to be employed in the patient group than in the age-, sex-, and municipality-matched reference groups, demonstrating that ESKD remains the main driver of unemployment in ESKD.
In our study, the age of the ESKD patients, especially those initiating dialysis, had a minimal effect on the employment rate. This finding is not in accordance with previous studies where younger age was associated with higher odds of being employed for both dialysis and transplant patients [9, 18–20]. Danuser et al. reported that younger patients were more likely to be employed before dialysis, which increased their chances of being employed during dialysis and post-transplantation [18]. In our study, both dialysis patients and the reference group aged 56–66 years had lower odds of being employed. This corresponds to the general tendency in OECD countries, where the frequency of employment decreases in those aged 55–64 years because they have passed the peak of their career and are approaching retirement [21].
Male sex led to higher odds of being employed among both groups of ESKD patients and their reference groups. This finding corresponds to the results of previous studies in kidney transplantation patients [19, 20, 22]. Bohlke et al. reported an OR of 2.7 for employment among men compared with women [22], whereas Eng et al. reported an OR of 1.8 [19]. In 2022, the OECD average female employment rate was approximately 16% lower than the OECD average for men (https://stats.oecd.org/index.aspx?queryid=103872). This general inequality in the employment rate between males and females was also reflected in our study, where the inequality was even higher among the ESKD patients than in the reference groups.
In our study, a higher educational level was associated with being employed in both dialysis and kidney transplantation patients as well as in the reference groups, which is in line with previous studies [9, 10, 18–20, 22–24]. Patients and those in the reference groups with a higher educational level may have more job opportunities, flexibility, and better healthcare options, which positively influence the possibilities for employment irrespective of chronic kidney failure.
We also found that having comorbidities such as diabetes or ischaemic heart disease was associated with lower ORs of being employed. This finding was in accordance with previous studies on diabetes [10, 20, 25], which reported ORs between 2 and 4.4 for being unemployed post transplantation in patients with diabetes. The diseases entail an increased risk of complications, which themselves increase the likelihood of being unemployed [18].
In this study, a shorter duration of dialysis (less than 24 months) and preemptive kidney transplantation were associated with higher odds of being employed, which is supported by results from previous studies [9, 18, 19, 23]. Limited time on dialysis or the complete avoidance of dialysis before transplantation may improve the chance of survival and lead to a better quality of life as well as the ability to remain at work.
In contrast with other studies, we found no association between donor type and being employed [9, 19, 22, 26, 27].
Peritoneal dialysis was also associated with increased odds of being employed, but the choice of dialysis modality may also be determined by employment status, as it is easier to stay employed with peritoneal dialysis [28, 29].
Our data showed that some factors affecting employment rates were more strongly associated with the reference group than with the ESKD groups. These variables included age (being younger than 56 years) and education (higher than primary school); ethnicity (immigrant) and having diabetes (dialysis patients), and ischaemic heart disease (transplantation patients). A possible explanation is that having a severe chronic kidney disease is so disruptive to health and work ability that it outweighs the influence of socioeconomic factors and comorbidities. Therefore, improving treatments for ESKD combined with social support to stay employed is important.
The odds of being employed increased over the time period for both dialysis and transplantation patients, with higher odds of employment in the period 2015–2019 compared to 2005–2009. During the years 2005–2019, there have been substantial improvements in the treatment of ESKD patients, which may be one of the explanations for the fact that it is easier to remain in work in 2015–2019. However, in the same period in Denmark there has been a higher employment rate and less unemployment in general. This will also make it easier for ESKD patients to stay employed.
Strengths and limitations
A major strength of this study was the inclusion of all Danish ESKD patients during a 15-year period and the comparison with a reference group from the general population representing the entire background population of Denmark. We used register-based data on employment in conjunction with relevant and detailed socioeconomic and health-related data. Furthermore, we used an independent assessment of employment in contrast with most previous studies that used self-reported data.
We divided the population into ‘in employment’ if the cohort member received no social transfer payments; ‘currently out of workforce’ if the cohort member received social transfer payments related to unemployment or sickness absence; or ‘permanently out of the workforce’ if the cohort member had retired or received either public or disability pensions. This division may underestimate the number of people in actual employment, as persons merely on short-term sick leave from their work will not be categorized as ‘in employment’ but rather as ‘currently out of the workforce,’ even though they still have a valid attachment to the workforce. We tried to remedy this situation by defining the index date for the transplanted cohort as 28 days prior to surgery to correctly identify patients who are only out of the workforce only due to their surgery.
Implications and perspectives
In summary, this study underscores the importance of offering early support to patients with chronic kidney disease to remain at work. It is also important to minimize the duration of dialysis and decrease the waiting time for transplantation.
Future studies could focus on analyzing data for ESKD patients at different stages of the disease course, both before dialysis and after transplantation, to assess when it is most relevant to initiate preventive measures to ensure that as few as possible lose their jobs.
Furthermore, nephrologists could be trained to identify ESKD patients who are at risk of dropping out of the labor market and to refer them to the authorities who can support patients in staying in work.
Achieving success in this endeavour requires close cooperation among healthcare professionals, rehabilitation institutions, companies, and employers. Furthermore, these efforts must be underpinned by robust social policies that ensure favourable working conditions and provide financial support for individuals with severe chronic kidney diseases, enabling them to remain active in the labour market.
Conclusion
The factors associated with being employed in both ESKD patients and the reference group were male sex, ethnicity, higher education, and the absence of comorbidities. These factors were more important for the ability to be employed in the reference group than in the ESKD groups, demonstrating that ESKD remains the main driver of unemployment in ESKD.
For kidney transplant recipients, a short duration of dialysis, preemptive transplantation, and a dialysis modality (peritoneal) were associated with increased odds of being employed.
Supplementary Information
Acknowledgements
None.
Abbreviations
- CI
Confidence interval
- DNPR
Danish national patient register
- DREAM
Danish register for evaluation of marginalization
- ESKD
End-stage kidney disease
- ICD-10
International classification of diseases, tenth revision
- OR
Odds ratio
- STROBE
Strengthening the reporting of observational studies in epidemiology
Authors’ contributions
LK, RKC, NHB designed the outline of the study. It was refined by JP, MSR, MO, and RKJ and FHG.MSR, RKJ, and FHG performed the data acquisition and analysis. LK drafted the primary manuscript. All authors reviewed and approved the manuscript before submission.
Funding
Open access funding provided by Copenhagen University. The study was supported by the Augustinus Foundation, project number 19-2123.
Data availability
Owing to the sensitivity of the data used, no dataset with microdata or pseudonymized data can be shared in accordance with Danish law and guidelines from the Danish Health Data Authority. Macrodata and information on data collection from registries and data from registries are available from the corresponding author upon reasonable request.
Declarations
Ethics approval and consent to participate
The study adheres to the tenets of the Declaration of Helsinki. The study only includes pseudonymized registry data and therefore does not require review of an ethics committee or consent from participants according to Danish Law (Scientific Ethical Committees Act § 14, part 2). The study was reviewed and approved by Statistics Denmark (project number 708072/MMK).
Consent for publication
Not applicable.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Data Availability Statement
Owing to the sensitivity of the data used, no dataset with microdata or pseudonymized data can be shared in accordance with Danish law and guidelines from the Danish Health Data Authority. Macrodata and information on data collection from registries and data from registries are available from the corresponding author upon reasonable request.