Relationship between reasons for intermittent missing patient-reported outcomes data and missing data mechanisms.

PURPOSE: Non-response (NR) to patient-reported outcome (PRO) questionnaires may cause bias if not handled appropriately. Collecting reasons for NR is recommended, but how reasons for NR are related to missing data mechanisms remains unexplored. We aimed to explore this relationship for intermittent NRs. METHODS: Patients with multiple myeloma completed validated PRO questionnaires at enrolment and 12 follow-up time-points. NR was defined as non-completion of a follow-up assessment within seven days, which triggered contact with the patient, recording the reason for missingness and an invitation to complete the questionnaire (denoted "salvage response"). Mean differences between salvage and previous on-time scores were estimated for groups defined by reasons for NR using linear regression with clustered standard errors. Statistically significant mean differences larger than minimal important difference thresholds were interpreted as "missing not at random" (MNAR) mechanism (i.e. assumed to be related to declining health), and the remainder interpreted as aligned with "missing completely at random" (MCAR) mechanism (i.e. assumed unrelated to changes in health). RESULTS: Most (7228/7534 (96%)) follow-up questionnaires were completed; 11% (802/7534) were salvage responses. Mean salvage scores were compared to previous on-time scores by reason: those due to hospital admission, mental or physical reasons were worse in 10/22 PRO domains; those due to technical difficulties/procedural errors were no different in 21/22 PRO domains; and those due to overlooked/forgotten or other/unspecified reasons were no different in any domains. CONCLUSION: Intermittent NRs due to hospital admission, mental or physical reasons were aligned with MNAR mechanism for nearly half of PRO domains, while intermittent NRs due to technical difficulties/procedural errors or other/unspecified reasons generally were aligned with MCAR mechanism.

Improved survival in myeloma patients-a nationwide registry study of 4,647 patients ≥75 years treated in Denmark and Sweden.

The prevalence of multiple myeloma (MM) is increasing in Nordic countries and the rest of the western world. Patients aged ≥75 years at diagnosis constitute an increasing proportion of all MM patients, but are underrepresented in randomized clinical trials. There is an urgent need for studies of the characteristics, treatment and outcome in this cohort. We present data from two nationwide population-based registries of all MM patients diagnosed in Denmark from January 1, 2005 until February 18, 2020, and in Sweden from January 1, 2008 until December 31, 2019, including treatment data for patients diagnosed until 2018 (Denmark) and 2019 (Sweden). In total 4,647 patients were ≥75 years at diagnosis, compared to 7,378 younger patients. Patients ≥75 years, accounting for approximately 40% of all MM patients, are a distinct cohort with more advanced disease at diagnosis, reflected by higher International Staging System (ISS) stage, and a higher proportion have renal failure and anemia. We found a more gradual introduction of modern medications in the older cohort than in the younger, despite simultaneous changes in guidelines. Compared to the cohorts in randomized controlled trials that guide the treatment of non-transplant eligible patients, we found a higher proportion of patients ≥75 years and presenting with ISS III in the real-world populations. Nevertheless, response rates and survival are increasing, indicating that modern treatment regimens are effective and well tolerated also in elderly MM patients in real-world populations.

Validation of the UK myeloma research alliance risk profile, a new clinical prediction model for outcome in patients with newly diagnosed multiple myeloma not eligible for autologous stem cell transplantation; a population-based study from the Danish national multiple myeloma registry.

In 2019 the UK Myeloma Research Alliance introduced the Myeloma Risk Profile (MRP) for prediction of outcome in patients with newly diagnosed multiple myeloma (MM), ineligible for autologous stem cell transplantation. To validate the MRP in a population-based setting we performed a study of the entire cohort of transplant ineligible MM patients above 65 years in the Danish National MM Registry. Our data confirmed the value of the MRP. In a cohort of 1,377 patients, the MRP score separated patients into three distinct risk-groups with an observed hazard ratio of 2.91 for early death in high-risk versus low-risk patients.