The present study shows that the increase in hospital resources far exceeds the increase in patient volume. A higher number of employees and particularly more doctors seem to be needed to treat each patient. Thus, if effectiveness and productivity for medical doctors in 2001 had been at the same level as in 1995, it might be speculated that they could have taken care of a hospital with on average 1110 in-hospital patients with the same case-mix, instead of only 793. One should, however, be careful in generalising results from one hospital, since national as well as international studies have shown that the consumption of hospital resources varies between different geographical regions [3, 9]. However, also in the present study some unexplained variations occur. Thus, there is no obvious explanation for the reduction in new referrals from 1999–2001, after a steady increase (Table 1). In 2002 new referrals had again increased to 100713 of a total volume of 281904 out-patient consultations (data not shown), still a reduction of 2.8% from 1995. The trend of an increased follow-up as a main driving force for total out-patient activity therefore seems to hold, particularly since this also was a steady trend in several departments (Table 4, Table 5). Furthermore, the macro-data from the present study is in agreement with national data for the same time period, with the greatest increase in activities seen in the medical departments , while surgical activities have been surprisingly stable, and even reduced for some departments.
Ashby and Altman studied hospital productivity during the period 1980–1989 by means of aggregate productivity, defined as the ratio of admissions (after adjusting for the complexity of the patients and outpatient activities) to FTEs . They found that while admissions and FTEs increased with an average of 1.4% and 1.7% per year respectively, aggregate productivity fell with an average of 0.4%. However, by also taken into account intensity of services and changes in intermediate productivity (defined as ratio of services to FTEs) they concluded that hospitals had become more efficient during the study period. However, no analysis of individual hospitals nor raw productivity data were given. Furthermore, even if the yearly increase in admissions in their study was similar to that in the present (1.4% vs. 1.6%), the increase in FTEs were much lower than in the present study (1.7% vs. 4.7%). This difference also supports the speculation that the (aggregate) productivity of St. Olavs Hospital was significantly reduced during the study period.
In a study of trends in structure, productivity, effectiveness and unit costs of hospital and community health services in England in 1997–1999  it was concluded that productivity had grown by a compound rate of 1.9% annually. The general trend did, however, conceal wide fluctuations. Furthermore, the trends were quite different from those found at St. Olavs Hospital, with a reduction in support staff (at St. Olavs Hospital these groups showed a considerable growth), and a reduction in unit labour costs, which at St. Olavs Hospital had risen significantly during the study period.
Based on the present findings several hypotheses might be generated and discussed to explain these developmental trends.
Increased focus on quality
Hospital performance and expenditure is not only related to patient volume but also to quality and intensity of treatment, as well as case-mix [10, 11]. It might therefore be argued that the increase in resource allocation could be related to improvement in treatment quality or changes in case-mix. Thus, during the study period there was an increased focus on quality, particularly in documentation of patient records and reports. This can partly explain the increase in office and administrative staff. On the other hand, admissions of high risk patient groups did not change, neither did in-hospital mortality for these patients, indicating that the severity of sickness or volume of these patients had not changed during the study period . Furthermore, the volume of diagnostic patient work-up, such as laboratory tests and imaging procedures were not increased during the study period, also indicating that complexity and case-mix of admitted patients had not been significantly changed. Thus, data related to treatment quality did not indicate significant changes in case-mix or treatment quality during the study period.
Bottlenecks and technological developments
Low productivity in hospitals has often been explained by bottlenecks, particularly in the medical service professions such as radiology and anaesthesiology [13, 14]. Since a reduction in these activities was seen both in volume/physician (laboratory services, radiology and anaesthesiology) and volume/patient (laboratory services, radiology) it is unlikely that these services were true bottlenecks in the treatment lines.
Also, during the study period no major technological developments or new diseases were introduced, although an increase in the use of cardiovascular stents and laparoscopic surgery was seen. The average patient treated in 2001 was therefore probably not more complicated to treat than in 1995.
Imbalance between hospital beds and medical resources
Another explanation that might be considered is related to the steady demand by hospital owners for increased effectiveness, reflected in a significant reduction in in-hospital days and average length of stay for each patient. It might be speculated that this trend actually creates more work with each patient by creating a need to see the patient again (in the department or at the outpatient clinic), because the work-up or treatment could not be fully completed during the short hospital stay. This hypothesis is also supported by national data showing that during the period from 1996 to 2003 the number of patients readmitted as an emergency case within 30 days after discharge increased from 8% to 9,6% of all emergency admissions . Furthermore, the number of patient with a single admission during a year was reduced from 57 to 55 per cent of the total number of admission . In a recent European study it was found that 24% of patients admitted to a department of internal medicine were readmitted within 6 months from discharge, with major impact on resource utilisation . One might therefore speculate if the reduction in the number of hospital beds as a measure to increase effectiveness (by reducing the length of stay), has actually resulted in an imbalance between staffing resources and available beds. It can therefore be hypothesised that if the hospital to some extent also had increased the number of beds in relation to the increase in manpower, instead of reducing them by 2% (Table 1), the productivity per employee might also have been increased in stead of being reduced.
Lack of professional continuity in patient care
There might also be organisational reasons for this development. With the increase in the number of doctors and interrupted working plans, it is difficult to organise the service so the physician who will be seeing the patient at the follow-up consultation at the outpatient clinic is the same who treated the patient while in the department. In the eye of the new doctor, the patient will also be new. This situation is likely to result in the schedule of another follow-up visit before the patient is referred back to the general practitioner. The (new) doctor might feel that this is necessary, but by medical criteria it might not be indicated. Private practitioners in Norway have thus complained that the hospitals keep referred patients too long with too many follow-up visits . This emphasises the need to have clinical guidelines (departmental or national) structuring necessary follow-up, particularly for major patient categories. This is an issue of such impact on hospital productivity and effectiveness that it should not be up to the individual doctor (often in-training) to decide.
Do hospitals lack patients?
The most striking finding in this study is the data concerning the outpatient population. The significant increase in the number of follow-up consultations, while new referral consultations actually went down must also raise the hypothesis that the slow increase in patient-related activities at the hospital, in spite of a significant increase in resource allocation, can be explained by a relative lack of patients. It might also be speculated if the relatively slow increase in the number of patients who are admitted might be explained in the same way. Data from the Norwegian Patient Registry show that from 1999 to 2000 the number of individuals admitted to Norwegian hospitals increased by 0,3%, while the number of admissions increased by 1,8% . The increased number of admissions is therefore to a large extent caused by re-admittance of patients recently discharged, and not by new patients taken in. It can be speculated that this reflects that the market (patient volume) might not be big enough in relation to the investments in increased production capacity (equipment and manpower) at hospitals. In this context the patient population might actually be a limited reserve. In agreement with this speculation, more hospitals and departments in Norway now advertise their services to patients in other health regions, possibly in order to recruit patients to keep up their activity. This is particularly evident in relation to surgery.
Hospital owners and politicians have for many years asked hospitals to increase their admissions and out-patient consultations to meet the seemingly unlimited demand for treatment. It might therefore be speculated that if patient population (volume) might be limited, the only possible answer to increase volume is to recycle the patients you already have. The modest increase in admitted patients and operations at the surgical departments, but significant increases in follow-up patient at the surgical outpatient clinics, might therefore reflect that it is easier to recycle a successfully operated patient for an extra consultation at the outpatient clinic than to readmit him. Most medical departments also show relatively similar developments in admitted patients and outpatients consultations. It can thus be speculated if the long waiting lists at St. Olavs University Hospital as well as at other Norwegian hospitals, are mainly caused by a tendency to readmit recently treated patients and once again see follow-up patients, instead of scheduling new patients from the waiting lists .
Finally, the fact that the patient population over time might be limited can also be related to general social-demographic trends. Although the general picture seems to be an increased demand for new treatments for new diseases or malfunctions, the other trend is an increasingly healthier population, partly because of increased focus on physical exercise, healthier food habits and less smoking. Focus on external hazards, such as traffic accidents have in spite of a significant increase in the number of automobiles resulted in a reduction in fatal accidents by 10% during the last ten years, while injuries have not increased more than the population size . Furthermore, the technological developments, which have made a major impact on hospital treatment, have also made it possible for patients to take care of and monitor their treatment in their own home and reduce the need for hospital visits . This developmental trend will probably continue.