BudgetState Hospitals / Hospitals
General hospital · Zwolle
Isala
Wait times over the norm69%
107 of 155 over the norm
Result€20 m
2025, margin 2.0%
Solvency33%
sector average 36% (2024)
Parking per hour€2.10
Zwolle
Locations
- Isala DiaconessenhuisHoogeveenseweg, 7943KA Meppel
- Isala Diaconessenhuis SteenwijkSluisweg, 8332JC Steenwijk
- Isala HeerdeEperweg, 8181ET Heerde
- Isala KampenEngelenbergplantsoen, 8266AB Kampen
- Isala klinieken, loc. ZwolleDokter van Heesweg, 8025AB Zwolle
Wait times
Latest report: 27 October 2026. Over the norm first. The colour measures a wait against the Treeknorm, the position against the other hospitals: position 1 is the shortest.
Over the norm, every fortnight
IsalaAll hospitals
Waits against the norm, by kind
within the Treeknormover it, up to one and a half timesmore than one and a half timesnot reported
Treatments
| For | Wait | Position | Median in the Netherlands25th–75th percentile | Location |
|---|---|---|---|---|
| Enlarged prostate surgeryUrology | 400 days | 57 of 57 | 61 days43–99 days | Isala Diaconessenhuis |
| Septoplasty (nasal septum surgery)ENT | 203 days | 57 of 61 | 81 days57–146 days | Isala klinieken, loc. Zwolle |
| Surgery for benign anal conditionsSurgery / Dermatology | 100 days | 48 of 55 | 49 days33–80 days | Isala klinieken, loc. Zwolle |
| Umbilical hernia repair in adultsSurgery | 100 days | 39 of 50 | 53 days34–97 days | Isala Diaconessenhuis |
| Groin hernia repairSurgery | 100 days | 52 of 65 | 49 days28–91 days | Isala klinieken, loc. Zwolle |
| Meniscus or knee ligament surgerySurgery / Orthopaedics | 92 days | 47 of 55 | 50 days33–75 days | Isala klinieken, loc. Zwolle |
| Breast reconstructionPlastic surgery | 75 days | 19 of 42 | 79 days52–130 days | Isala klinieken, loc. Zwolle |
| Dupuytren's contracture surgeryPlastic surgery | 75 days | 29 of 45 | 66 days42–96 days | Isala klinieken, loc. Zwolle |
| Gallbladder removalSurgery | 70 days | 50 of 63 | 43 days30–64 days | Isala Diaconessenhuis |
| Total knee replacementOrthopaedics | 70 days | 25 of 60 | 84 days45–117 days | Isala klinieken, loc. Zwolle |
| Tonsil or adenoid removalENT | 68 days | 40 of 63 | 60 days42–82 days | Isala klinieken, loc. Zwolle |
| Tooth extraction without general anaestheticOral and maxillofacial surgery | 65 days | 26 of 34 | 57 days29–64 days | Isala klinieken, loc. Zwolle |
| Grommets (ear tubes)ENT | 64 days | 50 of 61 | 37 days29–51 days | Isala klinieken, loc. Zwolle |
| Kidney stone removal through the skin (PCNL)Urology | 60 days | 16 of 25 | 49 days29–63 days | Isala klinieken, loc. Zwolle |
| Apicectomy (root-end surgery)Oral and maxillofacial surgery | 60 days | 22 of 31 | 39 days19–60 days | Isala klinieken, loc. Zwolle |
| Mohs surgeryDermatology | 60 days | 15 of 23 | 54 days42–83 days | Isala klinieken, loc. Zwolle |
| Incontinence or prolapse surgery (women)Gynaecology | 60 days | 25 of 61 | 71 days48–117 days | Isala klinieken, loc. Zwolle |
| HysterectomyGynaecology | 60 days | 28 of 58 | 64 days42–89 days | Isala klinieken, loc. Zwolle |
| Endovenous varicose vein treatmentDermatology | 58 days | 20 of 37 | 57 days42–78 days | Isala klinieken, loc. Zwolle |
| Knee arthroscopyOrthopaedics | 41 days | 22 of 46 | 42 days27–63 days | Isala klinieken, loc. Zwolle |
| Total hip replacementOrthopaedics | 40 days | 11 of 61 | 64 days42–90 days | Isala klinieken, loc. Zwolle |
| Prostate cancer surgeryUrology | 40 days | 17 of 29 | 35 days25–50 days | Isala Diaconessenhuis |
| Female sterilisationGynaecology | 40 days | 10 of 26 | 48 days35–89 days | Isala klinieken, loc. Zwolle |
| Trigger finger releasePlastic surgery | 38 days | 19 of 35 | 32 days23–51 days | Isala klinieken, loc. Zwolle |
| Eyelid surgeryOphthalmology | 38 days | 8 of 30 | 54 days39–89 days | Isala klinieken, loc. Zwolle |
| Carpal tunnel surgerySurgery / Plastic surgery / Orthopaedics | 38 days | 16 of 37 | 44 days21–59 days | Isala klinieken, loc. Zwolle |
| Cataract surgeryOphthalmology | 30 days | 14 of 56 | 49 days30–84 days | Isala klinieken, loc. Zwolle |
Outpatient clinic: first appointment
| For | Wait | Position | Median in the Netherlands25th–75th percentile | Location |
|---|---|---|---|---|
| Ophthalmology (general)Ophthalmology | 882 days | 58 of 58 | 59 days21–90 days | Isala klinieken, loc. Zwolle |
| Gastroenterology (general)Gastroenterology | 198 days | 57 of 66 | 98 days50–148 days | Isala klinieken, loc. Zwolle |
| Surgery (general)Surgery | 143 days | 66 of 66 | 14 days7–27 days | Isala Diaconessenhuis |
| Paediatrics (general)Paediatrics | 137 days | 63 of 65 | 35 days21–57 days | Isala Diaconessenhuis Steenwijk |
| Gynaecology (general)Gynaecology | 119 days | 52 of 68 | 72 days45–114 days | Isala Diaconessenhuis Steenwijk |
| Fertility problemsGynaecology | 106 days | 51 of 55 | 60 days38–80 days | Isala klinieken, loc. Zwolle |
| Neurology (general)Neurology | 77 days | 39 of 67 | 64 days48–90 days | Isala Kampen |
| Slipped disc in the backNeurology | 62 days | 22 of 37 | 57 days46–92 days | Isala klinieken, loc. Zwolle |
| ProctologySurgery | 55 days | 39 of 47 | 25 days13–48 days | Isala klinieken, loc. Zwolle |
| Plastic surgery (general)Plastic surgery | 48 days | 54 of 63 | 24 days10–42 days | Isala klinieken, loc. Zwolle |
| Urology (general)Urology | 47 days | 46 of 66 | 32 days20–60 days | Isala klinieken, loc. Zwolle |
| EndocrinologyInternal medicine | 37 days | 16 of 49 | 48 days29–67 days | Isala klinieken, loc. Zwolle |
| RehabilitationRehabilitation | 36 days | 21 of 40 | 36 days21–43 days | Isala klinieken, loc. Zwolle |
| Sports medicineSports medicine | 36 days | 16 of 26 | 26 days11–43 days | Isala klinieken, loc. Zwolle |
| Rheumatology (general)Rheumatology | 35 days | 20 of 60 | 47 days29–90 days | Isala Diaconessenhuis |
| CataractOphthalmology | 35 days | 34 of 47 | 20 days8–40 days | Isala Diaconessenhuis |
| Slipped disc in the neckNeurosurgery | 35 days | 5 of 19 | 46 days39–67 days | Isala klinieken, loc. Zwolle |
| Dermatology (general)Dermatology | 34 days | 30 of 66 | 35 days28–70 days | Isala klinieken, loc. Zwolle |
| Neurosurgery (general)Neurosurgery | 31 days | 17 of 41 | 42 days22–63 days | Isala klinieken, loc. Zwolle |
| Pain managementAnaesthesiology | 27 days | 18 of 65 | 58 days23–90 days | Isala Heerde |
| Internal medicine (general)Internal medicine | 24 days | 16 of 68 | 42 days24–61 days | Isala klinieken, loc. Zwolle |
| NephrologyInternal medicine | 23 days | 19 of 51 | 33 days19–50 days | Isala klinieken, loc. Zwolle |
| Respiratory medicine (general)Respiratory medicine | 22 days | 30 of 68 | 28 days13–42 days | Isala klinieken, loc. Zwolle |
| Vascular surgerySurgery | 21 days | 36 of 62 | 18 days10–30 days | Isala klinieken, loc. Zwolle |
| Slipped disc in the backNeurosurgery | 21 days | 5 of 22 | 46 days23–62 days | Isala klinieken, loc. Zwolle |
| Cardiology (general)Cardiology | 14 days | 13 of 68 | 28 days16–45 days | Isala Kampen |
| Hip problemsOrthopaedics | 14 days | 25 of 51 | 14 days7–24 days | Isala Diaconessenhuis |
| Medical oncologyInternal medicine | 10 days | 26 of 49 | 9 days6–15 days | Isala klinieken, loc. Zwolle |
| ENT (general)ENT | 9 days | 9 of 66 | 21 days12–30 days | Isala Heerde |
| Oral and maxillofacial surgeryOral and maxillofacial surgery | 7 days | 5 of 57 | 31 days15–59 days | Isala klinieken, loc. Zwolle |
| Breast clinicSurgery | 3 days | 30 of 59 | 3 days2–5 days | Isala Diaconessenhuis |
| Paediatric neurologyPaediatrics | 0 days | 1 of 35 | 37 days22–47 days | Isala klinieken, loc. Zwolle |
| Paediatric cardiologyPaediatrics | 0 days | 1 of 34 | 31 days18–55 days | Isala klinieken, loc. Zwolle |
| Groin herniaSurgery | 0 days | 1 of 52 | 17 days7–28 days | Isala klinieken, loc. Zwolle |
| Orthopaedics (general)Orthopaedics | 0 days | 1 of 59 | 14 days7–30 days | Isala Diaconessenhuis Steenwijk |
Tests
| For | Wait | Position | Median in the Netherlands25th–75th percentile | Location |
|---|---|---|---|---|
| CT scanRadiology | 40 days | 61 of 63 | 14 days9–22 days | Isala klinieken, loc. Zwolle |
| Bone density scan (DEXA)Radiology | 31 days | 41 of 60 | 18 days12–38 days | Isala Diaconessenhuis |
| Abnormal cervical smearGynaecology | 14 days | 10 of 46 | 17 days14–30 days | Isala Diaconessenhuis |
| X-rayRadiology | 12 days | 60 of 61 | 1 days0–1 days | Isala Diaconessenhuis |
| Ultrasound scanRadiology | 12 days | 28 of 66 | 13 days8–17 days | Isala Diaconessenhuis |
| Sleep apnoea testingENT / Respiratory medicine / Neurology | 10 days | 3 of 40 | 45 days25–70 days | Isala Diaconessenhuis |
| MammogramRadiology | 7 days | 35 of 62 | 5 days2–10 days | Isala Diaconessenhuis |
Quality per treatment
Report year 2025, as the hospital reported it, beside the median of all hospitals.
Pancreatic cancer
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Pancreatic head resections (Whipple)number per year | 57 | 44 |
| Severe complications after surgerylower is better | 26.5% | 32.3% |
| Died within 30 days of surgerylower is better | 2.6% | 2.4% |
| Median wait in days until treatmentlower is better | 36 | 32 |
Tonsil or adenoid removal
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Re-operation for bleeding within 14 days (tonsils)lower is better | 4.3% | 2.6% |
| Re-operation for bleeding within 14 days (adenoids)lower is better | 0.6% | 0.0% |
Abdominal aortic aneurysm
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Aortic aneurysm or dissection repairsnumber per year | 129 | 69 |
| Died within 30 days after repair of a ruptured aneurysmlower is better | 19.1% | 24.2% |
| Died within 30 days after repair of an intact aneurysmlower is better | 1.1% | 1.5% |
| Uncomplicated recovery after planned repair (textbook outcome)higher is better | 65.2% | 76.0% |
Stroke
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Stroke patientsnumber per year | 1,322 | 570 |
| Median minutes from arrival to clot-busting treatmentlower is better | 25 | 29 |
Bladder cancer
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Bladder removals for bladder cancernumber per year | 46 | 42 |
| Urologists performing bladder removalsnumber of specialists | 3 | 3 |
| Severe complications within 30 days of surgerylower is better | 15.2% | 15.0% |
| Died within 30 days of surgerylower is better | 0.0% | 0.9% |
Breast implants
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Removed or replaced for a complication within 60 days (reconstruction)lower is better | 2.6% | 2.6% |
| Removed or replaced for a complication within 60 days (cosmetic)lower is better | 0.0% | 0.0% |
| Removed or replaced for a complication, day 61 to 365 (reconstruction)lower is better | 15.2% | 3.3% |
| Removed or replaced for a complication, day 61 to 365 (cosmetic)lower is better | 2.0% | 0.0% |
Breast cancer
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Breast cancer patients operated onnumber per year | 461 | 216 |
| Surgical oncologists treating breast cancernumber of specialists | 5 | 4 |
| Plastic surgeons treating breast cancer patientsnumber of specialists | 9 | 3 |
| Median days from diagnosis to start of treatmentlower is better | 35 | 32 |
Chronic kidney disease and dialysis
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Started dialysis with a working fistula or PD catheterhigher is better | 42.9% | 64.2% |
Bowel cancer
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Colon cancer resectionsnumber per year | 122 | 78 |
| Rectal cancer resectionsnumber per year | 49 | 30 |
| Died within 90 days of rectal surgerylower is better | 1.4% | 0.0% |
| Complicated recovery after colon surgerylower is better | 11.1% | 11.6% |
| Complicated recovery after rectal surgerylower is better | 19.5% | 20.2% |
| Died within 90 days of colon surgerylower is better | 2.0% | 2.2% |
| Median days from diagnosis to treatment (colon)lower is better | 43 | 36.8 |
Diabetes
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Diabetes patients treated by the paediatriciannumber per year | 339 | 99 |
| Diabetes patients treated by the internistnumber per year | 3,163 | 1,350 |
| Paediatrician: blood sugar on target (HbA1c below 58)higher is better | 59.9% | 47.8% |
| Internist: blood sugar on target (HbA1c below 58)higher is better | 45.1% | 42.3% |
| Paediatrician: blood sugar far too high (HbA1c above 86)lower is better | 2.1% | 5.9% |
| Internist: blood sugar far too high (HbA1c above 86)lower is better | 3.7% | 5.3% |
Coronary angioplasty (PCI)
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Died within 30 days of angioplasty (PCI)lower is better | 2.5% | 2.6% |
| Died within 1 year of angioplasty (PCI)lower is better | 4.4% | 5.1% |
| Unplanned repeat procedure on the same vessel within 1 yearlower is better | 2.7% | 2.6% |
Peripheral arterial disease
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Certified vascular surgeonsnumber of specialists | 5 | 4 |
| Vascular interventional radiologistsnumber of specialists | 6 | 4 |
Gallbladder removal (gallstones)
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Readmitted for a complication within 30 days of surgerylower is better | 3.3% | 2.8% |
Hip fracture
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Hip fractures treatednumber per year | 668 | 293 |
| Mobility score after 3 months, fully mobile before (1 = best)lower is better | 2.2 | 2.6 |
| ADL help needed after 3 months, independent before (0 = none)lower is better | 1.1 | 1.3 |
Gynaecological cancer
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Debulking operations for ovarian cancernumber per year | 60 | 60 |
| Operations for endometrial cancernumber per year | 147 | 64 |
| Tumour fully removed at primary debulking (ovary)higher is better | 75.0% | 90.8% |
| Complicated recovery after ovarian debulking (adjusted)lower is better | 2.9% | 6.9% |
| Complicated recovery after keyhole hysterectomy (adjusted)lower is better | 0.0% | 0.0% |
| Died within 30 days of ovarian debulking (adjusted)lower is better | 0.0% | 0.0% |
| Median days from first visit to debulking surgerylower is better | 54.5 | 35.2 |
Carotid artery surgery
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Carotid artery proceduresnumber per year | 65 | 48 |
| Died within 30 days of the procedurelower is better | 0.9% | 0.8% |
| Bleeding within 30 dayslower is better | 2.6% | 2.5% |
| Neurological event within 30 dayslower is better | 1.7% | 2.0% |
| Uncomplicated recovery (textbook outcome)higher is better | 81.2% | 79.8% |
Slipped disc or spinal stenosis
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Re-operation within 30 dayslower is better | 0.7% | 0.4% |
| Spinal fluid leak during surgerylower is better | 0.3% | 0.3% |
| Deep wound infectionlower is better | 0.2% | 0.0% |
| More muscle weakness right after surgerylower is better | 0.0% | 0.0% |
Hip replacement
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Hip replacementsnumber per year | 844 | 421 |
| Orthopaedic surgeons performing hip revisionsnumber of specialists | 3 | 4 |
| Orthopaedic surgeons placing hip replacementsnumber of specialists | 9 | 5 |
| Deep wound infection within 90 dayslower is better | 0.7% | 0.7% |
| Average hip score gain (OHS) after 12 monthshigher is better | — | 18.6 |
| Average drop in pain when active after 12 monthshigher is better | — | 5.8 |
| Revision within 1 year (adjusted)lower is better | 0.3% | 0.9% |
Incontinence or prolapse in women
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Much or very much better after surgeryhigher is better | 83.7% | 90.8% |
Cancer care (general)
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Kidney cancer operationsnumber per year | 11 | 54 |
| Colon resectionsnumber per year | 220 | 131 |
| Rectal resectionsnumber per year | 98 | 46 |
| Resections of liver metastasesnumber per year | 90 | 36 |
| Thyroid cancer patients operated onnumber per year | 20 | 18 |
| Gynaecologic oncologists in FTEnumber of specialists | 2 | 2.6 |
Knee replacement
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Total knee replacementsnumber per year | 547 | 310 |
| Partial knee replacementsnumber per year | 168 | 79 |
| Orthopaedic surgeons performing knee revisionsnumber of specialists | 2 | 3 |
| Orthopaedic surgeons placing knee replacementsnumber of specialists | 10 | 5 |
| Deep wound infection within 90 dayslower is better | 0.3% | 0.4% |
| Average knee score gain (OKS) after 12 monthshigher is better | — | 15.3 |
| Average drop in pain when active after 12 monthshigher is better | — | 4.9 |
| Revision within 3 years (adjusted)lower is better | 0.6% | 1.3% |
Liver surgery
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Liver resectionsnumber per year | 66 | 50 |
| Uncomplicated recovery after liver surgery (adjusted)higher is better | 85.8% | 84.4% |
Lung cancer
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Lung resectionsnumber per year | 75 | 64 |
| Lung cancer patients given curative radiotherapynumber per year | 177 | 174 |
| Died within 90 days of stereotactic radiotherapylower is better | 2.1% | 0.8% |
| Died within 30 days of lung surgerylower is better | 1.1% | 0.9% |
| Complicated recovery after lung surgerylower is better | 8.1% | 12.6% |
| Died within 90 days of chemoradiotherapylower is better | 4.9% | 1.1% |
Melanoma
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| New patients with inoperable melanoma (stage III/IV)number per year | 70 | 67 |
| Alive 1 year after diagnosis (stage III/IV)higher is better | 64.5% | 62.3% |
| Alive 2 years after diagnosis (stage III/IV)higher is better | 46.8% | 48.2% |
Surgery for children
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Groin and scrotal operations in childrennumber per year | 222 | 43 |
| Operations for pyloric stenosisnumber per year | — | 15 |
Prostate cancer
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Prostate removals for prostate cancernumber per year | 127 | 186 |
| Urologists performing prostate removalsnumber of specialists | 4 | 4 |
| Severe complications within 30 days of surgerylower is better | 3.9% | 2.2% |
| PSA still detectable (above 0.1) 6 months after surgerylower is better | 8.9% | 5.7% |
Emergency department
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Patients with severe multiple injuries receivednumber per year | 273 | 33 |
Cataract surgery
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Better sight after surgery (at least 1 line gained)higher is better | 94.7% | 94.5% |
| Within 0.5 dioptre of the target strength after 4-6 weekshigher is better | 77.8% | 77.7% |
Spinal fusion
| Indicator | Isala | Median in the Netherlands |
|---|---|---|
| Re-operation within 30 dayslower is better | 0.0% | 3.1% |
| Spinal fluid leak during surgerylower is better | 0.0% | 0.7% |
| Deep wound infectionlower is better | 0.0% | 2.0% |
| More muscle weakness right after surgerylower is better | 0.0% | 0.0% |
Annual accounts
Figures of Stichting Isala Klinieken, from its public annual accounts.
| Year | Revenue | Costs | Result | Margin | Equity | Solvency | Cash |
|---|---|---|---|---|---|---|---|
| 2025filed 28 May 2026 | €982 m | €956 m | €20 m | 2.0% | €253 m | 33.2% | €5.7 m |
| 2024filed 28 May 2025 | €921 m | €893 m | €24 m | 2.6% | €234 m | 31.3% | €147 m |
| 2023filed 21 May 2024 | €860 m | €854 m | −€2.0 m | -0.2% | €210 m | 29.0% | €98 m |
| Sector average, General hospital (2024) | |||||||
| 2024 | — | — | — | 2% | — | 36% | — |
Staff
| Year | Care staff | Sick leave | Long-open vacancies |
|---|---|---|---|
| 2025 | 4,397 | 6.4% | 6 |
| 2024 | 4,907 | 5.9% | 4 |
| 2023 | — | — | — |
Care staff: the average number of people in care. Sick leave: the care staff's sickness absence. Long open: vacancies open for three months or more.
Board and supervision
As the register lists them with the annual accounts for 2025.
Board of directors
- Hillechiena Harmina KuperBestuurder · since 20 September 2023
- Michèla Christina Alberta BlomBestuurder · since 20 September 2023
- Wouter Lourens VreemanBestuurder · since 1 February 2025
Supervisory board
- Riekele Hendrik van Terwisgavoorzitter Raad van Toezicht · since 20 September 2023
- Jacob Kievitlid van Raad van Toezicht · since 20 September 2023
- Margarethe Akkeline Christine Kasper - de Kroonlid van Raad van Toezicht · since 20 September 2023
- Ronald Wilhelmus Lambertus Spanjerslid van Raad van Toezicht · since 20 September 2023
- Mélanie Hélène Koelemaijlid van Raad van Toezicht · since 1 December 2023
- Gerardus Henricus Adrianus Maria van Berlo; lid van Raad van Toezicht · since 1 April 2024
Parking
Zwolle
€2.10 an hour. The first 20 minutes free. Daily maximum €9.30.
Start fee €1.20, then €0.70 or €0.60 per 20 minutes (up to €2.10 per hour); free on Sundays and public holidays.
Read on the hospital's website, 2 November 2026.