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| 2. |
- Ranstam, Jonas, et al.
(författare)
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Health-care quality registers: outcome-orientated ranking of hospitals is unreliable.
- 2008
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Ingår i: Journal of Bone and Joint Surgery: British Volume. - 2044-5377. ; 90:12, s. 1558-1561
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Tidskriftsartikel (refereegranskat)abstract
- Public disclosure of outcome-orientated ranking of hospitals is becoming increasingly popular and is routinely used by Swedish health-care authorities. Whereas uncertainty about an outcome is usually presented with 95% confidence intervals, ranking's based on the same outcome are typically presented without any concern for bias or statistical precision. In order to study the effect of incomplete registration of re-operation on hospital ranking we performed a simulation study using published data on the two-year risk of re-operation after total hip replacement. This showed that whereas minor registration incompleteness has little effect on the observed risk of revision, it can lead to major errors in the ranking of hospitals. We doubt whether a level of data entry sufficient to generate a correct ranking can be achieved, and recommend that when ranking hospitals, the uncertainties about data quality and random events should be clearly described as an integral part of the results.
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| 3. |
- Ranstam, Jonas, et al.
(författare)
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Statistical analysis of arthroplasty register data.
- 2010
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Ingår i: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 81, s. 10-14
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Data from arthroplasty registers are often analyzed using survival methods. Several methodological problems exist, for example relating to competing events, non-random censoring, non-proportional hazards and dependent observations. League tables and ranking of specific survival results leds to further methodological difficulties. Most of these problems are, however, well known and a number of methods for dealing successfully with the problems have been developed. These methods are usually accessible in commercially available statistical software packages. The statistical analysis and reporting of data from arthroplasty registers can thus be improved. Development of arthroplasty register guidelines for statistical analysis could play an important role in making these registers even more useful.
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| 4. |
- Ranstam, Jonas, et al.
(författare)
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The Cox model is better than the Fine and Gray model when estimating relative revision risks from arthroplasty register data
- 2017
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Ingår i: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3674 .- 1745-3682. ; , s. 1-3
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose — Analysis of the revision-free survival of knee and hip prostheses has traditionally been performed using Kaplan–Meier analysis and Cox regression. The competing risk problem that is related to patients who die during follow-up has recently been increasingly discussed, not least with regard to the problem of choosing a suitable statistical method for the analysis. We compared the results from analyses of Cox models and Fine and Gray models. Methods — We used data simulation based on parameter estimates from the Swedish Knee Arthroplasty Register and assessed hypothetical effects of the studied risk factors. Results — The Cox model provided more adequate results. Interpretation — The parameter estimates from the Fine and Gray model can be misleading if interpreted in terms of relative risk.
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| 5. |
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| 6. |
- Robertsson, Otto, et al.
(författare)
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The Swedish Knee Arthroplasty Register: a review.
- 2014
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Ingår i: Bone & joint research. - : British Editorial Society of Bone & Joint Surgery. - 2046-3758. ; 3:7, s. 217-222
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Forskningsöversikt (refereegranskat)abstract
- We are entering a new era with governmental bodies taking an increasingly guiding role, gaining control of registries, demanding direct access with release of open public information for quality comparisons between hospitals. This review is written by physicians and scientists who have worked with the Swedish Knee Arthroplasty Register (SKAR) periodically since it began. It reviews the history of the register and describes the methods used and lessons learned. Cite this article: Bone Joint Res 2014;3:217-22.
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| 8. |
- W-Dahl, Annette, et al.
(författare)
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An examination of the effect of different methods of scoring pain after a total knee replacement on the number of patients who report unchanged or worse pain.
- 2014
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Ingår i: The Bone & Joint Journal. - 2049-4408. ; 96B:9, s. 1222-1226
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Tidskriftsartikel (refereegranskat)abstract
- We identified a group of patients from the Swedish Arthroplasty Register who reported no relief of pain or worse pain one year after a total knee replacement (TKR). A total of two different patient-reported pain scores were used during this process. We then evaluated how the instruments used to measure pain affected the number of patients who reported no relief of pain or worse pain, and the relative effect of potential risk factors. Between 2008 and 2010, 2883 TKRs were performed for osteoarthritis in two Swedish arthroplasty units. After applying exclusion criteria, 2123 primary TKRs (2123 patients) were included in the study. The Knee injury and Osteoarthritis Outcome Score (KOOS) and a Visual Analogue Scale (VAS) for knee pain were used to assess patients pre-operatively and one year post-operatively. Only 50 of the 220 patients (23%) who reported no pain relief on either the KOOS pain subscale or the VAS for knee pain did so with both of these instruments. Patients who reported no pain relief on either measure tended to have less pain pre-operatively but a higher degree of anxiety. Charnley category C was a predictor for not gaining pain relief as measured on a VAS for knee pain. The number of patients who are not relieved of pain after a TKR differs considerably depending on the instrument used to measure pain. Cite this article: Bone Joint J 2014;96-B:1222-6.
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| 9. |
- Wagner, Philippe, et al.
(författare)
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Increased cancer risks among arthroplasty patients: 30year follow-up of the Swedish Knee Arthroplasty Register.
- 2011
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Ingår i: European Journal of Cancer. - : Elsevier BV. - 1879-0852 .- 0959-8049. ; 47:7, s. 1061-1071
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: An increasing number of young patients are undergoing knee arthroplasties. Thus, the long-term risks of having a knee prosthesis must be evaluated. This study focuses on the potential carcinogenic effects of the prosthesis; it is a long-term follow-up of all patients in Sweden between 1975 and 2006. METHODS: The incidence of cancer in a total population of operated individuals was compared to the overall national cancer incidence in Sweden by means of standardised incidence ratios. Analysis of cancer latency period was performed to identify potential aetiological factors. RESULTS: For male and female patients with rheumatoid arthritis (RA) or osteoarthritis (OA), the overall cancer risks were elevated, ranging from 1.10 (95% confidence interval (CI): 1.03-1.18) for men with OA to 1.26 (1.23-1.29) for men with RA. The greatest increases in risk were observed for the leukaemia subtypes, myelodysplastic syndromes (MDS) and essential thrombocytosis (ET), ranging from 3.31 (1.24-8.83) for ET in men with OA to 7.38 (1.85-29.51) for ET in women with RA. Increases in risk were also observed for breast cancer, prostate cancer and melanoma. The latency analysis revealed elevated risks late in the study period for both solid and haematopoietic cancers. However, only increases in MDS and possibly prostate cancer and melanoma rates appeared to be connected to the operation. CONCLUSION: This study showed that OA and RA arthroplasty patients have a significantly higher risk of cancer than the general population. Elevated risks of MDS and possibly prostate cancer and melanoma indicated a potential connection to exposure to metals in the implant. The observed excessive incidence of ET was likely associated with the inflammatory disease.
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| 10. |
- Wagner, Philippe, et al.
(författare)
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Metal-on-metal joint bearings and hematopoetic malignancy A review
- 2012
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Ingår i: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 83:6, s. 553-558
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Forskningsöversikt (refereegranskat)abstract
- This is a review of the hip arthroplasty era. We concentrate on new metal bearings, surface replacements, and the lessons not learned, and we highlight recent reports on malignancies and joint implants. A low incidence of blood malignancies has been found in bone marrow taken at prosthetic surgery. The incidence is increased after replacement with knee implants that release very low systemic levels of metal ions. A carcinogenic effect of the high levels of metal ions released by large metal-on-metal implants cannot be excluded. Ongoing Swedish implant registry studies going back to 1975 can serve as a basis for evaluation of this risk.
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