Table 3 Overview of reinforcing loops and balancing loops in the causal loop diagram. For each loop, it is noted whether the loop describes an intended or unintended consequence of a policy/action, or an initiative beyond the organisational boundary of stakeholders implementing a particular policy or action

Balancing loops

B1

3 → 4 → 3

Stringency of regulations to approve new HD centres determines pressure on the registration system (intended control measure)

B2

3 → 7 → 3

Investment in quality assurance capacity affects the adequacy of the quality assurance system (initiative outside organisational boundary)

B3

1 → 10 → 1

Quality of HD services (predominantly session length and adherence to infection control measures) is influenced by level of demand for HD services (intended control action)

B4

15 → 16 → 15

Providing HD patients with temporary access (via a catheter) affects demand for vascular access (intended control action)

B5

5 → 2 → 5

Changes in supply of HD services affect the deficit of HD nurses (unintended consequence)

B6

2 → 18 → 2

The magnitude of the HD nurse deficit influences the level of overlapping nurse shifts and overtime work for HD nurses (intended control action)

B7

2 → 19 → 20 → 2

Number of HD nurses trained depends on demand for HD nurses (initiative outside of organisational boundary)

B8

2 → 17 → 2

Deficit of HD nurses affects the rate at which PD nurses switch to HD (system control measure)

B9

23 → 24 → 22 → 23

Adequacy of the PD system for number of PD patients affects PD quality of care (system response to changes in number of PD patients)

B10

24 → 25 → 26 → 24

Investment in PD capacity depends on perceived adequacy of PD system (intended control action)

Reinforcing loops

R1

3 → 4 → 5 → 6 → 1 → 3

Changes in regulations to approve new HD centres can induce demand for HD services (unintended consequence)

R2

3 → 4 → 8 → 7 → 3

Changes in regulations to approve new HD centres influence investment in quality assurance capacity (unintended consequence)

R3

1 → 10 → 11 → 12 → 13 → 1

Quality of HD service provision affects financial incentives for doctors to refer patients for HD (unintended consequence)

R4

15 → 16 → 17 → 15

Number of HD patients with temporary access alters long-term demand for vascular access services (unintended consequence)

R5

15 → 16 → 11 → 12 → 13 → 1 → 15

Changes in number of patients with temporary HD access influences financial incentives for doctors to refer patients for HD (unintended consequence)

R6

3 → 4 → 5 → 12 → 13 → 1 → 3

Changes in HD supply influence financial incentives for doctors to refer patients for HD (unintended consequence)

R7

2 → 18 → 21 → 20 → 2

Measures to cope with HD nurse deficit affect rates of HD nurse burnout (unintended consequence)

R8

2 → 18 → 11 → 12 → 13 → 1 → 5 → 2

Measures to cope with HD nurse deficit influence financial incentives for doctors to refer patients to HD (unintended consequence)

R9

2 → 17 → 22 → 23 → 1 → 5 → 2

Rate at which PD nurses switch to HD influences level of demand to increase HD supply (consequence of system change)

R10

23 → 27 → 22 → 23

Quality of PD depends on level of experience and culture for PD (system response)

Solution loops

B1a

3 → S1 → 1 → 3

Pre-authorisation of patients according to available supply controls pressure on regulatory system

B2a

7 → S2b → 7

With key performance indicators (KPI) for the adequacy of quality assurance mechanisms, adequacy of registration systems to meet demand affects level of investment in quality assurance mechanisms

B3a

10 → 11 → S3b → 10

With quality-based payments per patient to HD service providers, rate of complications affects level of investment in quality of care

B3b

1 → 10 → 11 → S3b → 13 → 14 → 1

Investment in quality of care affects financial incentives for doctors to refer patients to HD

B4a

16 → 11 → 16

With quality-based payments per patient to HD service providers, rate of complications regulates number of HD patients with temporary access

B4b

15 → S1 → 1 → 15

Pre-authorisation of patients according to available supply controls pressure on vascular access services

B6a

2 → 18 → S5b → S5c → 21 → 20 → 2

With enforceable regulations restricting HD patients per nurse and HD nurse maximum hours per week, punishment for HD centres not adhering to the rules regulates level of HD nurse burnout

B7a

19 → 20 → S4b → 19

Performance indicators linked to availability of trained HD nurses for the Ministry of Public Health regulate HD nurse training relative to nurse deficit

B8a

18 → 11 → S3c → 18

Demand forecasting for HD nurse training by the Ministry of Public Health changes nurses trained according to anticipated demand for HD services

B9a

2 → 17 → 22 → 23 → 1 → S4b → 19 → 20 → 2

With a KPI target for HD nurse to patient ratio, changes in HD demand influence HD nurse training

R9a

23 → S7 → 1 → 17 → 22 → 23

Pre-authorisation of patients initiating HD provides external regulatory control to the balance of PD to HD patients

R10a

23 → 26 → 24 → 22 → 23

Proactive forecasting for PD capacity links investment in PD infrastructure and nurses to anticipated need