Evaluation of the SwedeAmp database: Focus on coverage and amputation level rates.

Background: The National Board of Health and Welfare manages several national registers in Sweden. This includes the Swedish National Inpatient Register (IPR), covering all surgical operations, and SwedeAmp, focusing on outcomes after lower limb amputations (LLA). However, coverage rates of amputation levels between these registers have not been externally analyzed.

Objective: To compare SwedeAmp's coverage with IPR for LLA cases and to assess SwedeAmp's accuracy in capturing LLA data. The goal of this study was also to identify potential discrepancies and establish benchmarks for common amputation levels.

Methodology: Data from both registers, covering the years 2018 to 2023, were compared regarding the amputation levels and patient demographics. The coverage rate of the SwedeAmp register was calculated using SwedeAmp data as the numerator and IPR data as the denominator.

Findings: The IPR registry recorded 10,788 LLAs across 21 regions (67 hospitals). The SwedeAmp documented 5,246 LLAs covering 17 regions (36 hospitals), leaving 5,542 amputations unaccounted for, mainly due to regions or hospitals not participating in the SwedeAmp registry and lower registration rates in some areas. Key findings include:Achieving full coverage in SwedeAmp (17 regions) would require registering 9,305 LLAs.Both men and women over 85 years were significantly underrepresented.Thirteen regions in SwedeAmp obtained more than 40% coverage rate.5 regions had more than 50% rate of above-knee amputations (range: 50.9% - 68.2%).8 regions reporting more than 50% rate of below-knee amputations (range: 53.1% - 88.9%).Among the 67 hospitals performing LLAs, 36 reported to SwedeAmp. Six of these hospitals performed fewer than 10 LLAs over a six-year period.

Conclusion: SwedeAmp captured 48.6% of initial LLAs in Sweden, highlighting the need for improved data completeness in LLA records, especially as only 13 regions achieved over 40% Coverage. For hospitals performing regular amputation, the proposed benchmark-coverage of ≥60%, with ≤36.3% for transfemoral amputation (TF), ≤8.4% for knee disarticulations (KD), and ≥55.3% for transtibial amputations (TT) - could serve as a target to enhance consistency and accuracy in reporting. Expanding coverage can improve the register's utility in tracking outcomes, setting national standards, aiding research, and supporting clinical decision-making.