Purpose: The etiology of pain in osteoarthritis (OA) is complex andmultifactorial. A growing number of studies suggest that modificationof pain-transmission in the peripheral and central nervous system,leading to sensitization, plays a role in OA pain. Sensitization seems tobe associated with neuropathic pain-like symptoms and assessment ofthese symptoms can help to identify patients who could benefit fromadditional treatment options. Several questionnaires are available todistinguish neuropathic from nociceptive pain symptoms. The modifiedpainDETECT questionnaire (mPDQ) is a self-reported questionnairedeveloped to discriminate between nociceptive- and possible/likelyneuropathic pain in knee OA patients. Recently the mPDQ was translatedinto Dutch and adjusted to also fit hip OA patients. The aim of thisstudy was to assess the validity of the mPDQ-NL in patients with hip orknee OA.Methods: Primary hip and knee OA patients were recruited from threeDutch hospitals. Based on previous research, confirmatory factor analysisfor two principal components was performed to assess structuralvalidity. Construct validity (both convergent and divergent) wasassessed using hypothesis testing. Predefined hypotheses were formulatedconcerning the correlation between the mPDQ-NL and theSelf-reported Leeds Assessment of Neuropathic Symptoms and Signs (SLANSS),subscales of the Knee injury and Osteoarthritis Outcome score/Hip disability and Osteoarthritis Outcome Score (KOOS/HOOS), VisualAnalogue Scale for pain (VAS pain), and subscales of the RAND-36health survey (RAND-36). According to the COSMIN criteria, constructvalidity of a questionnaire is sufficient if 75% of predefined hypothesesare met. Additionally, convergent validity was assessed with blunt PainPressure Thresholds (PPTs) in a subsample of participants. A reducedPPT is a somatosensory abnormality that is considered an indication ofsensitization in OA. Therefore it was expected that reduction of PPTswas associated with higher mPDQ scores.Results: 168 participants were included. PPT measurements wereperformed in a sample of 46 participants. Factor analysis confirmed twoprincipal components. The items that loaded on the first componentcould be described as “evoked neuropathic sensations”, the items thatloaded on the second component as “spontaneous neuropathic sensations”.However there were two items that substantially loaded on bothcomponents. The item regarding pain pattern did not load on anycomponent. Considering construct analysis, 80% of the predefinedhypotheses concerning the correlation between mPDQ and self-reportedquestionnaires were met. Considering the correlation with PPTmeasurements, 50% of the predefined hypotheses were met.Conclusions: The mPDQ-NL seems to adequately reflect neuropathicpain-like symptoms experienced by hip and knee OA patients. Concerningstructural validity, two determinative components seem to bepresent, in line with previous research. However, one particular itemregarding pain pattern might not reflect the construct of neuropathicpain-like symptoms in hip or knee OA. Therefore, when using the mPDQin hip or knee OA patients, it might be considered to skip this particularitem. Construct validity can be considered sufficient, with over 75% ofthe predefined hypotheses regarding correlation between the mPDQNLand other questionnaires were met. However, only 50% of the hypotheses concerning PPT measurements were met, probably due toheterogeneity and limited sample size of this subgroup. To ourknowledge, this study is the first to assess the structural validity of themPDQ knee and hip by using factor analysis and to assess constructvalidity using elaborate hypothesis testing as proposed by the COSMINguidelines.
Background Physical activity after bariatric surgery is associated with sustained weight loss and improved quality of life. Some bariatric patients engage insufficiently in physical activity. The aim of this study was to examine whether and to what extent both physical activity and exercise cognitions have changed at one and two years post-surgery, and whether exercise cognitions predict physical activity. Methods Forty-two bariatric patients (38 women, 4 men; mean age 38 ± 8 years, mean body mass index prior to surgery 47 ± 6 kg/m²), filled out self-report instruments to examine physical activity and exercise cognitions pre- and post surgery. Results Moderate to large healthy changes in physical activity and exercise cognitions were observed after surgery. Perceiving less exercise benefits and having less confidence in exercising before surgery predicted less physical activity two years after surgery. High fear of injury one year after surgery predicted less physical activity two years after surgery. Conclusion After bariatric surgery, favorable changes in physical activity and exercise cognitions are observed. Our results suggest that targeting exercise cognitions before and after surgery might be relevant to improve physical activity.
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Aim and method: To examine in obese people the potential effectiveness of a six-week, two times weekly aquajogging program on body composition, fitness, health-related quality of life and exercise beliefs. Fifteen otherwise healthy obese persons participated in a pilot study. Results: Total fat mass and waist circumference decreased 1.4 kg (p = .03) and 3.1 cm (p = .005) respectively. The distance in the Six-Minute Walk Test increased 41 meters (p = .001). Three scales of the Impact of Weight on Quality of Life-Lite questionnaire improved: physical function (p = .008), self-esteem (p = .004), and public distress (p = .04). Increased perceived exercise benefits (p = .02) and decreased embarrassment (p = .03) were observed. Conclusions: Aquajogging was associated with reduced body fat and waist circumference, and improved aerobic fitness and quality of life. These findings suggest the usefulness of conducting a randomized controlled trial with long-term outcome assessments.
