Mapping chronic liver disease questionnaire scores onto SF-6D utility values in patients with primary sclerosing cholangitis.

PURPOSE: The chronic liver disease questionnaire (CLDQ) is a frequently used liver-specific quality of life instrument, but it does not provide information on preference-adjusted health status, which is essential for cost-utility analysis. We aimed to develop a mapping function deriving utilities from the CLDQ in primary sclerosing cholangitis (PSC). METHODS: Short form-6D (SF-6D) utilities were calculated from SF-36 data collected in a recent prospective study in which unselected patients with PSC also completed the CLDQ. Ordinary least squares (OLS), generalized linear, median, and kernel regression analyses were employed to devise a mapping function predicting utilities. This was validated in three random subsamples of the cohort and in a separate sample of PSC patients following liver transplantation. Adjusted R (2) and root-mean-square error (RMSE) as well as Pearson's r coefficients and mean absolute errors between predicted and observed values were used to determine model performance. RESULTS: Decompensated liver disease and fatigue, systemic symptoms, and emotional distress, assessed with the CLDQ, were related to worse SF-6D utilities. The final OLS prediction model explained 66.3 % of the variance in the derivation sample. Predicted and observed utilities were strongly correlated (r = 0.807, p < 0.001), but the mean absolute error (0.0604) and adjusted RMSE (10.6 %) were of intermediate size. Similar model characteristics were observed after employment of generalized linear and median regression models and at validation. CONCLUSIONS: A model has been constructed, showing good validity predicting SF-6D utilities from CLDQ scores at the group level in PSC. Further testing is required to externally validate the model.

The potential for a generally applicable mapping model between QLQ-C30 and SF-6D in patients with different cancers: a comparison of regression-based methods.

PURPOSE: To establish and compare generalized or "global" mapping relationships between QLQ-C30 and SF-6D, applicable across different cancer types. METHODS: Patients (N = 671) with breast, myeloma, colorectal, lymphoma, bone marrow, prostate, lung and gastroenteric cancer were randomly split into estimation (75%) and validation (25%) datasets. SF-6D was estimated from QLQ-C30 scores via ordinary least squares, generalized linear models and median (least-absolute deviations) regression approaches, and with Bayesian additive regression kernels. Predictive ability was assessed with root mean square error, mean absolute error and proportions of predictions with absolute errors >0.05 and >0.1, whereas explanatory power with adjusted R (2) or equivalent fit measures. Two external samples (breast and colorectal cancer) were used to further test the models. RESULTS: The QLQ-C30's global health item, the physical, emotional and social functioning scales, and the fatigue, pain and diarrhea symptom scales were significant predictors (p < 0.05 or better) in all models. Negligible deviations in models' performance were observed. All models overpredicted utilities for patients in worst health and underpredicted them for those in better health (p < 0.01 or better). Regarding external validation, performance was better in the colorectal cancer than in the breast cancer sample. CONCLUSIONS: This study has provided evidence to support the use of "global" mapping models to predict SF-6D utilities from QLQ-C30 in patients with different cancers. Testing with diverse patient samples is required to confirm the generalizability (or not) of mapping models across cancer conditions.

Investigating demographic, work-related and job satisfaction variables as predictors of motivation in Greek nurses.

AIM: To investigate whether demographic variables and work-related factors predict work motivation in Greek nurses. BACKGROUND: Nurses' motivation is crucial for an effective health-care system. Herzberg's and Maslow's motivation theories constitute the framework of this study. METHOD: The sample consisted of 200 nurses from every sector and registration level in a University Hospital in Greece. The response rate was 76%. INSTRUMENTS: A previously developed and validated questionnaire addressing four work-related motivators (job attributes, remuneration, co-workers and achievements) on a five-point Likert scale. RESULTS: Most participants were women, married, between 36 years and 45 years old and higher education graduates. The highest mean score was recorded for 'achievements' (mean 4.07, SD 0.72), which emerged as the most important motivator. Job satisfaction, work sector and age were statistically significantly related to motivational factors. CONCLUSIONS: Nurses placed emphasis on motivators not strictly relating to economic rewards, but which can be seen as intrinsic and could lead to self-actualization. IMPLICATIONS FOR NURSING MANAGEMENT: The constantly changing health sector requires that human resources and job context be a priority for health administrators. By promoting nurses' satisfaction and efficacy, an improvement in service quality is expected.

Psychometric properties of the Greek Diabetes Treatment Satisfaction Questionnaire.

OBJECTIVES: Measurement of treatment satisfaction in diabetes is important as it has been shown to be associated with positive outcomes, reduced disease cost and better health. The aim of this study was to assess the construct validity and internal consistency reliability of the Greek version of the Diabetes Treatment Satisfaction Questionnaire (DTSQ). METHODS: A sample of type II diabetes patients (N = 172) completed the DTSQ status version, the SF-36 health survey and also provided data regarding treatment method, clinical and socio-demographic status. Instrument structure, reliability (Cronbach's a) and construct validity (convergent, discriminative, concurrent and known-groups) were assessed. RESULTS: The DTSQ measurement properties were confirmed in the Greek version with confirmatory factor analysis (CFA). Scale reliability was high (Cronbach's a = 0.92). Item-scale internal consistency and discriminant validity were also good, exceeding the designated success criteria. Significant correlations were observed between DTSQ items/overall score and SF-36 scales/component scores, which were hypothesized to measure similar dimensions. Known groups' comparisons yielded consistent support of the construct validity of the instrument. CONCLUSIONS: The instrument was well-accepted by the patients and its psychometric properties were similar to those reported in validation studies of other language versions. Further research, incorporating a longitudinal study design, is required for examining test-retest reliability and responsiveness of the instrument, which were not addressed in this study. Overall, the present results confirm that the DTSQ status version is a reasonable choice for measuring diabetes treatment satisfaction in Greece.

Reliability and validity of the Greek QLQ-C30 and QLQ-MY20 for measuring quality of life in patients with multiple myeloma.

OBJECTIVES: The aim of this study was to assess the psychometric properties of the Greek EORTC QLQ-C30 and QLQ-MY20 instruments. METHOD: A sample of myeloma patients (N = 89) from two tertiary hospitals were surveyed with the QLQ-C30, QLQ-MY20 and various demographic and disease related questions. The previously validated Greek SF-36 instrument was used as a "gold standard" for health-related quality of life (HRQoL) comparisons. Hypothesized scale structure, internal consistency reliability (Cronbach's alpha) and various forms of construct validity (convergent, discriminative, concurrent and known-groups) were assessed. RESULTS: Multitrait scaling confirmed scale structure of the QLQ-C30 and QLQ-MY20, with good item convergence (96% and 72%) and discrimination (78% and 58%) rates. Cronbach's α was >0.70 for all but one scale (cognitive functioning). Spearman's correlations between similar QLQ-C30 and SF-36 scales ranged between 0.35-0.80 (P < 0.001). Expected interscale correlations and known-groups comparisons supported construct validity. QLQ-MY20 scales showed comparatively lower correlations with QLQ-C30 functional scales, and higher correlations with conceptually related symptom scales. CONCLUSIONS: The observed psychometric properties of the two instruments imply suitability for assessing myeloma HRQoL in Greece. Future studies should focus on generalizability of the results, as well as on specific issues such as longitudinal validity and responsiveness.

Comparing health-related quality of life of cancer patients under chemotherapy and of their caregivers.

INTRODUCTION: Cancer is a major disorder physically and psychologically affecting both patients and their caregivers. In this study, health-related quality of life (HRQoL) of patient-caregiver dyads during the period of chemotherapy was assessed. MATERIAL AND METHODS: Two hundred twenty-two cancer patient-caregiver dyads were enrolled in the study, which was conducted from October 2008 to March 2009. HRQoL was evaluated with EQ-5D. RESULTS: The mean age of the sample was 57.4 and 48.9 for patients and caregivers, respectively. The EQ-5D descriptive system indicates that female patients more frequently experience anxiety and depression than male patients. Male and higher-education caregivers had higher VAS scores, while demographic factors did not seem to influence patients' HRQoL. Anxiety and depression of caregivers were correlated with patients' problems in self-care and usual activities. CONCLUSIONS: Quality of life is highly influenced during the period of chemotherapy for both patients and caregivers and is often under reported. Interventions that can improve HRQoL, especially in the domain of mental health for both cancer patients and their caregivers, need to be implemented.

Motivation and job satisfaction among medical and nursing staff in a Cyprus public general hospital.

BACKGROUND: The objective of this study was to investigate how medical and nursing staff of the Nicosia General Hospital is affected by specific motivation factors, and the association between job satisfaction and motivation. Furthermore, to determine the motivational drive of socio-demographic and job related factors in terms of improving work performance. METHODS: A previously developed and validated instrument addressing four work-related motivators (job attributes, remuneration, co-workers and achievements) was used. Two categories of health care professionals, medical doctors and dentists (N = 67) and nurses (N = 219) participated and motivation and job satisfaction was compared across socio-demographic and occupational variables. RESULTS: The survey revealed that achievements was ranked first among the four main motivators, followed by remuneration, co-workers and job attributes. The factor remuneration revealed statistically significant differences according to gender, and hospital sector, with female doctors and nurses and accident and emergency (A+E) outpatient doctors reporting greater mean scores (p < 0.005). The medical staff showed statistically significantly lower job satisfaction compared to the nursing staff. Surgical sector nurses and those >55 years of age reported higher job satisfaction when compared to the other groups. CONCLUSIONS: The results are in agreement with the literature which focuses attention to management approaches employing both monetary and non-monetary incentives to motivate health care professionals. Health care professionals tend to be motivated more by intrinsic factors, implying that this should be a target for effective employee motivation. Strategies based on the survey's results to enhance employee motivation are suggested.

Disease activity and sleep quality in rheumatoid arthritis: a deeper look into the relationship.

Objectives: This study looks deeper into the relationship between rheumatoid arthritis (RA) disease activity and distinct dimensions of sleep quality. Methods: The Pittsburgh Sleep Quality Index (PSQI) was administered to a cohort of 147 RA patients. Health-related quality of life (HRQoL) and fatigue were measured with the SF-12 and Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) instruments, respectively, whereas RA activity was determined with the Disease Activity Score 28 joints (DAS28). Ethical approval for the study and informed consent from the participants were obtained. Results: Most patients were females (78.2%), and the mean age of the entire sample was 63.7 years. Most participants (77.6%) were poor sleepers (i.e. PSQI ≥ 5) who suffered from fatigue more than good sleepers (FACIT-F: 21.6 vs. 39.3, p < 0.001). Overall sleep quality correlated, in the expected directions, with disease activity (Spearman's rho = 0.87, p < 0.001), physical health (-0.66, p < 0.001), mental health (-0.71, p < 0.001), and fatigue (0.87, p < 0.001). PSQI and its component scores differed across patient subgroups with increasing RA activity, even after adjusting for confounding variables. Conclusion: RA disease activity distinctly affects sleep quality, and given the already demonstrated importance of good sleep, this 'deeper look' might contribute to the effort to improve HRQoL in RA patients.

Mapping the cancer-specific EORTC QLQ-C30 to the preference-based EQ-5D, SF-6D, and 15D instruments.

OBJECTIVES: To estimate models, via ordinary least squares regression, for predicting Euro Qol 5D (EQ-5D), Short Form 6D (SF-6D), and 15D utilities from scale scores of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30). METHODS: Forty-eight gastric cancer patients, split up into equal subgroups by age, sex, and chemotherapy scheme, were interviewed, and the survey included the QLQ-C30, SF-36, EQ-5D, and 15D instruments, along with sociodemographic and clinical data. Model predictive ability and explanatory power were assessed by root mean square error (RMSE) and adjusted R(2) values, respectively. Pearson's r between predicted and reported utility indices was compared. Three random subsamples, half in size the initial sample, were created and used for "external" validation of the modeling equations. RESULTS: Explanatory power was high, with adjusted R(2) reaching 0.909, 0.833, and 0.611 for 15D, SF-6D, and EQ-5D, respectively. After normalization of RMSE to the range of possible values, the prediction errors were 12.0, 5.4, and 5.6% for EQ-5D, SF-6D, and 15D, respectively. The estimation equations produced a range of utility scores similar to those achievable by the standard scoring algorithms. Predicted and reported indices from the validation samples were comparable thus confirming the previous results. CONCLUSIONS: Evidence on the ability of QLQ-C30 scale scores to validly predict 15D and SF-6D utilities, and to a lesser extent, EQ-5D, has been provided. The modeling equations must be tried in future studies with larger and more diverse samples to confirm their appropriateness for estimating quality-adjusted life-year in cancer-patient trials including only the QLQ-C30.

Valuation and preliminary validation of the Greek 15D in a sample of patients with coronary artery disease.

OBJECTIVE: To replicate, using the Greek version of the 15D instrument, the three-stage valuation procedure, using a sample of coronary artery disease patients; to assess on a preliminary basis the psychometric properties of the instrument in the Greek health-care environment; to evaluate the health-related quality of life of patients with coronary artery disease. METHODS: The generic instrument 15D was translated and culturally adapted into the Greek language and setting. It was then administered during October 2005 to May 2006 to 420 coronary artery disease patients. The three-stage valuation procedure was employed and, with the use of elicited preference weights, a single health-related quality of life index score for the patients was derived. Scores were also calculated using the original Finnish valuation system and compared with the previously derived utilities. Sensitivity, reliability, and validity were assessed by examining response distributions, floor and ceiling effects, item-scale correlations, Cronbach's alpha coefficients, and hypothesized relationships between sociodemographic variables and health-related quality of life. RESULTS: The Greek valuation systematically generated higher 15D utilities than the Finnish one. Nevertheless, the utilities derived with the original Finnish valuation algorithm differed significantly with respect to sex, age, and education, just as they did using the Greek valuation system. In most cases, the full range of possible responses has been used satisfactorily and floor and ceiling effects were generally moderate. In general, internal consistency reliability was also satisfactory. CONCLUSION: The valuation system generated results demonstrating satisfactory psychometric properties. Further research should validate the 15D in the general Greek population.

Comparing SF-6D and EQ-5D utilities across groups differing in health status.

OBJECTIVES: To compare the EQ-5D and SF-6D within socio-demographic and clinical groups in a representative sample (n = 1,005) of the Greek general population and to examine mean utility differences across groups differing in health in this population and in a highly morbid disease sample (diabetes, n = 215). METHODS: Association and level of agreement between instruments were estimated with Pearson's r and the intraclass correlation coefficient (ICC), respectively. Paired-samples t-test was used to identify significant score differences, which were regarded as minimally important differences (MID) when they exceeded 0.03. The EQ-VAS was used to classify individuals into health status groups, covering the range from very poor to very good health, and the same classification was used in the diabetes sample. RESULTS: EQ-5D and SF-6D were in agreement and strongly correlated over the entire sample (ICC = 0.536, P < 0.001 and r = 0.662, P < 0.001), but correlation varied according to socio-demographic factors and clinical conditions. In healthier responders, EQ-5D scores were significantly higher than SF-6D scores (P < 0.001) and differences constituted MIDs. Contrarily, in individuals with clinical conditions, SF-6D scores were predominantly higher than EQ-5D. The pattern of results was replicated in the disease sample as well. CONCLUSIONS: The hypotheses that EQ-5D generates higher scores in healthier populations and the SF-6D in less healthier groups were confirmed. Based on the evidence provided here, EQ-5D and SF-6D measuring discrepancies generate utility differences across VAS-based health groups, which warrant further within-sample investigation.

Identifying important motivational factors for professionals in Greek hospitals.

BACKGROUND: The purpose of this study was to identify important motivational factors according to the views of health-care professionals in Greek hospitals and particularly to determine if these might differ in the public and private sectors. METHODS: A previously developed -and validated- instrument addressing four work-related motivators (job attributes, remuneration, co-workers and achievements) was used. Three categories of health care professionals, doctors (N = 354), nurses (N = 581) and office workers (N = 418), working in public and private hospitals, participated and motivation was compared across socio-demographic and occupational variables. RESULTS: The range of reported motivational factors was mixed and Maslow's conclusions that lower level motivational factors must be met before ascending to the next level were not confirmed. The highest ranked motivator for the entire sample, and by professional subgroup, was achievements (P < 0.001). Within subgroups, motivators were similar, and only one significant difference was observed, namely between doctors and nurses in respect to co-workers (P < 0.05). Remuneration (and salary in particular) was reported as a significant incentive only for professionals in managerial positions. Health professionals in private hospitals were motivated by all factors significantly more than their public-hospital counterparts. CONCLUSION: The results are in agreement with the literature which focuses attention to management approaches employing both monetary and non-monetary incentives to motivate health care workers. This study showed that intrinsic factors are particularly important and should become a target for effective employee motivation.

Gender- and age-related benefit of renal replacement therapy on health-related quality of life.

OBJECTIVES: The aim of this study was to compare the health-related quality of life (HRQOL) of end-stage renal disease patients on renal replacement therapy with that of subjects of the same gender and similar age from the general population, in an attempt to determine patient subgroup that benefits more from the treatment. METHODS: A cross-sectional study involving haemodialysis, peritoneal dialysis and renal transplant patients (n = 874) was conducted with subjects providing socio-demographic and disease-related data, and completing the validated Greek Short Form-36 (SF-36) Health Survey. Patient-specific z-scores were calculated using mean SF-36 scores and SD of age- and gender-matched subgroups from the Greek norms. RESULTS: Males and younger patients generally reported better HRQOL. However, z-scores in these groups generally showed a larger health deficit, i.e. an increased divergence from the HRQOL of their age- and gender-matched counterparts of the general population, compared with the health deficit observed in female and younger patients. CONCLUSIONS: Health-related quality of life studies involving disease groups may sometimes be inconclusive if results are not compared with population norms, and particularly with subgroups matched for important demographic variables. Otherwise, as this study has shown, it is possible that important information may remain unrevealed.

Validity of the EuroQoL (EQ-5D) instrument in a Greek general population.

OBJECTIVES: The main purpose of this study was to assess the construct validity of the Greek EQ-5D instrument in measuring health-related quality of life, as well as to address the issues of concurrent validity, internal consistency reliability, and sensitivity. METHODS: A stratified, representative sample (n = 1388) of the Greek general population was approached for interview (response rate 72.4%). The survey included the EQ-5D, the SF-36, and questions on sociodemographic and clinical characteristics of the sample. RESULTS: The EQ-5D dimensions, the EQ visual analog scale, and the UK-based utility index were capable of distinguishing between groups of respondents, in the expected manner, on the basis of sex, age, education, socioeconomic status, self-reported health problems, and health services utilization, thus providing evidence of construct validity. Convergent and divergent validity of the EQ-5D descriptive system were supported by expected relationships with SF-36 scale and summary scores. Additionally, reporting a problem in a given EQ dimension was generally associated with lower SF-36 scores, supporting concurrent validity. Internal consistency reliability and sensitivity were also satisfactorily demonstrated. CONCLUSIONS: The results provide initial support for the construct validity of the EQ-5D in Greece, and, in conjunction to future studies addressing test-retest reliability and responsiveness, they support administering the instrument in health status studies, which in turn can contribute to transnational comparisons.

An estimate of lifelong costs and QALYs in renal replacement therapy based on patients' life expectancy.

OBJECTIVES: To estimate lifelong costs and quality adjusted life years (QALYs) of hemodialysis (HD), peritoneal dialysis (PD) and renal transplantation (Tx) in Greece, based on individual patient life expectancy. METHODS: A nationally representative patient sample on each modality, HD: N=642, PD: N=65 and Tx: N=167, was self-administered the SF-36 Health Survey, from which the preference-based SF-6D utility index was derived. Lifelong QALYs were estimated from literature-based expected remaining life years according to age, gender and modality. Cost analyses were performed from the perspective of the health system. Costs and QALYs were discounted at 5% and sensitivity analyses were performed. RESULTS: Estimated lifelong QALYs were 4.37 (HD), 3.94 (PD) and 16.11 (Tx) (P<0.001). Annual HD and PD costs per patient were estimated at euro36,247 and euro30,719 respectively. For Tx, average 1st year, 3-year and lifelong (undiscounted) costs were euro31,714, euro43,275 and euro151,274 respectively. Cost per QALY was higher in HD (euro60,353) compared to PD (euro54,504) and 1st year Tx (euro45,523). CONCLUSIONS: HD is used by 75% of the Greek ESRD patients, hence cost-saving efforts must be intensified. Reconsidering supply and reimbursement policies for dialyzers and drugs, establishing satellite dialysis units and adopting telemedicine in remote areas could be explored. Wider use of PD is also in the direction of increasing cost-effectiveness. Finally, efforts are required for disseminating the idea of organ donation.

Children's and parents' perspectives of health-related quality of life in newly diagnosed adolescent idiopathic scoliosis.

The aim of this study is to compare child and parent perceptions of health-related quality of life in Adolescent Idiopathic Scoliosis. The scoliosis-specific SRS-22 and the generic KIDSCREEN-52 were administered to newly diagnosed patients and the latter also to a parent. Strong correlations (r > 0.5, p < 0.001) were revealed between conceptually similar dimensions of the instruments. Parents' assessments of their child's HRQoL were generally higher than the children/adolescents; however score differences were small and insignificant. The significance of parents' perceptions was also confirmed with OLS regressions. In conclusion, HRQoL is thoroughly investigated when both generic and disease-specific instruments are used.

Are condition-specific utilities more valid than generic preference-based ones in asthma? Evidence from a study comparing EQ-5D-3L and SF-6D with AQL-5D.

BACKGROUND: Systematic discrepancies have been shown in utility values derived from different instruments. This study compares utilities from the condition-specific AQL-5D and the generic EQ-5D-3L and SF-6D in an asthmatic population with heterogeneous health-related quality of life (HRQoL), disease severity, and control status. METHODS: A consecutive sample of 104 patients diagnosed with asthma completed a survey containing the Greek versions of SF-36, EQ-5D-3L, and AQLQ(s). Treatment adequacy was assessed with the Asthma Control Questionnaire (ACQ), and asthma severity according to Global Initiative for Asthma 2016 guidelines. Association and agreement between instruments were assessed with Spearman's correlation and Bland-Altman plots. RESULTS: AQL-5D utilities exceeded (p < 0.001) those from EQ-5D-3L and SF-6D. There were weak-to-moderate correlations (<0.5) between most dimensions of AQL-5D, and those of EQ-5D-3L and SF-6D, and strong correlations between similar dimensions of EQ-5D-3L and SF-6D. Significant differences (p < 0.001) were observed throughout the visual analog scale (VAS), asthma severity and asthma control subgroups, with AQL-5D consistently higher than EQ-5D-3L and SF-6D. CONCLUSIONS: All instruments distinguished between differing degrees of asthma control, but only AQL-5D discriminated between asthma severity and HRQoL as well. Although the relatively small sample warrants caution in interpreting the subgroup results, this study contributes to the growing number of comparisons between condition-specific and generic preference-based instruments.

Health-Related Quality of Life and Association With Arthropathy in Greek Patients with Hemophilia.

Health-related quality of life (HRQoL) is increasingly implicated in contemporary hemophilia management. This study focuses on the assessment of HRQoL in Greek patients with hemophilia and the comparison with normative data from the general population, as well as on the extent arthropathy may affect the patients' HRQoL. One hundred and nine adult patients completed the Greek social functioning (SF-36) and Haem-A-QoL questionnaires. Arthropathy was assessed by both the World Federation of Hemophilia clinical score and Pettersson radiological score. The most impaired domains of Haem-A-QoL were sports/leisure (SL) and physical health (PH; mean scores 61.2 and 42.2, respectively). The patients experienced statistically significant lower mean scores in all SF-36 domains than the normative sample, especially in role physical (RPH), bodily pain (BP), and general health (GH) subscales. Among Haem-A-QoL subscales, SL and PH were found strongly associated with severity of arthropathy using both orthopedic scores ( P < .001), and maintained the statistical significance after adjustment for age ( P < .05). A poor orthopedic status was also negatively associated with certain SF-36 subscales. However, none of these correlations remained after adjustment with age. Compared to normative data from Greece, patients with hemophilia showed deterioration in all HRQoL subscales, with a more pronounced effect in RPH, BP, and GH subscales. Health-related quality of life was strongly influenced by arthropathy, mainly in the physical aspects of HRQoL. The use of the disease-specific Haem-A-QoL tool can capture additional associations between HRQoL and hemophilic arthropathy.

The effect of environmental factors on technical and scale efficiency of primary health care providers in Greece.

BACKGROUND: The purpose of this study was to compare technical and scale efficiency of primary care centers from the two largest Greek providers, the National Health System (NHS) and the Social Security Foundation (IKA) and to determine if, and how, efficiency is affected by various exogenous factors such as catchment population and location. METHODS: The sample comprised of 194 units (103 NHS and 91 IKA). Efficiency was measured with Data Envelopment Analysis (DEA) using three inputs, -medical staff, nursing/paramedical staff, administrative/other staff- and two outputs, which were the aggregated numbers of scheduled/emergency patient visits and imaging/laboratory diagnostic tests. Facilities were categorized as small, medium and large (<15,000, 15,000-30,000 and >30,000 respectively) to reflect catchment population and as urban/semi-urban or remote/island to reflect location. In a second stage analysis, technical and scale efficiency scores were regressed against facility type (NHS or IKA), size and location using multivariate Tobit regression. RESULTS: Regarding technical efficiency, IKA performed better than the NHS (84.9% vs. 70.1%, Mann-Whitney P < 0.001), smaller units better than medium-sized and larger ones (84.2% vs. 72.4% vs. 74.3%, Kruskal-Wallis P < 0.01) and remote/island units better than urban centers (81.1% vs. 75.7%, Mann-Whitney P = 0.103). As for scale efficiency, IKA again outperformed the NHS (89.7% vs. 85.9%, Mann-Whitney P = 0.080), but results were reversed in respect to facility size and location. Specifically, larger units performed better (96.3% vs. 90.9% vs. 75.9%, Kruskal-Wallis P < 0.001), and urban units showed higher scale efficiency than remote ones (91.9% vs. 75.3%, Mann-Whitney P < 0.001). Interestingly 75% of facilities appeared to be functioning under increasing returns to scale. Within-group comparisons revealed significant efficiency differences between the two primary care providers. Tobit regression models showed that facility type, size and location were significant explanatory variables of technical and scale efficiency. CONCLUSION: Variations appeared to exist in the productive performance of the NHS and IKA as the two main primary care providers in Greece. These variations reflect differences in primary care organization, economical incentives, financial constraints, sociodemographic and local peculiarities. In all technical efficiency comparisons, IKA facilities appeared to outperform NHS ones irrespective of facility size or location. In respect to scale efficiency, the results were to some extent inconclusive and observed differences were mostly insignificant, although again IKA appeared to perform better.