Chronic pain patients can be classified into four groups: Clustering-based discriminant analysis of psychometric data from 4665 patients referred to a multidisciplinary pain centre (a SQRP study).

OBJECTIVE: To subgroup chronic pain patients using psychometric data and regress the variables most responsible for subgroup discrimination. DESIGN: Cross-sectional, registry-based study. SETTING AND SUBJECTS: Chronic pain patients assessed at a multidisciplinary pain centre between 2008 and 2015. METHODS: Data from the Swedish quality registry for pain rehabilitation (SQRP) were retrieved and analysed by principal component analysis, hierarchical clustering analysis, and partial least squares-discriminant analysis. RESULTS: Four subgroups were identified. Group 1 was characterized by low "psychological strain", the best relative situation concerning pain characteristics (intensity and spreading), the lowest frequency of fibromyalgia, as well as by a slightly older age. Group 2 was characterized by high "psychological strain" and by the most negative situation with respect to pain characteristics (intensity and spreading). Group 3 was characterized by high "social distress", the longest pain durations, and a statistically higher frequency of females. The frequency of three neuropathic pain conditions was generally lower in this group. Group 4 was characterized by high psychological strain, low "social distress", and high pain intensity. CONCLUSIONS: The identification of these four clusters of chronic pain patients could be useful for the development of personalized rehabilitation programs. For example, the identification of a subgroup characterized mainly by high perceived "social distress" raises the question of how to best design interventions for such patients. Differentiating between clinically important subgroups and comparing how these subgroups respond to interventions is arguably an important area for further research.

A fixed protocol for outpatient clinic routines in the care of patients with severe renal failure.

BACKGROUND: The primary aim of this study was to assess whether a fixed protocol, using a specially trained team, for intermediate follow-up to fulfillment of guideline targets is non-inferior to conventional follow-up in the care of uraemic patients. A secondary aim was to investigate possible impact on patient outcome. METHODS: The cohort comprised 424 patients from seven centers. Inclusion criteria were either serum creatinine exceeding 200 µmol/l or calculated clearance below 30 ml/min, representing CKD 4 or 5a. Six centers followed a standardized protocol (group 1). One center provided controls (group 2). The study design was prospective and interventional. The variables measured were blood hemoglobin, bicarbonate, calcium, phosphate, intact parathyroid hormone, albumin, renal function variables, blood pressure and RAAS blockade. The number of patients achieving the set goals was analyzed as a time trend to determine if the intervention resulted in an improvement. RESULTS: At baseline, group 1 had significantly lower GFR and higher serum creatinine, calcium, phosphate, calcium × phosphate product and bicarbonate, lower mean arterial pressure (MAP), systolic blood pressures and less use of RAAS. During the intervention, group 1 improved in the direction of guidelines for blood hemoglobin, albumin, bicarbonate and MAP. Outcome of secondary endpoints gave a risk of death of 30% in both groups, while the risk of renal replacement therapy was higher in group 1. CONCLUSIONS: However, the time to renal replacement therapy was significantly shorter in the intervention group, indicating that other variables than guideline achievements are important for the patient.