Privacy Preserving Probabilistic Record Linkage (P3RL): a novel method for linking existing health-related data and maintaining participant confidentiality.

BACKGROUND Record linkage of existing individual health care data is an efficient way to answer important epidemiological research questions. Reuse of individual health-related data faces several problems: Either a unique personal identifier, like social security number, is not available or non-unique person identifiable information, like names, are privacy protected and cannot be accessed. A solution to protect privacy in probabilistic record linkages is to encrypt these sensitive information. Unfortunately, encrypted hash codes of two names differ completely if the plain names differ only by a single character. Therefore, standard encryption methods cannot be applied. To overcome these challenges, we developed the Privacy Preserving Probabilistic Record Linkage (P3RL) method. METHODS In this Privacy Preserving Probabilistic Record Linkage method we apply a three-party protocol, with two sites collecting individual data and an independent trusted linkage center as the third partner. Our method consists of three main steps: pre-processing, encryption and probabilistic record linkage. Data pre-processing and encryption are done at the sites by local personnel. To guarantee similar quality and format of variables and identical encryption procedure at each site, the linkage center generates semi-automated pre-processing and encryption templates. To retrieve information (i.e. data structure) for the creation of templates without ever accessing plain person identifiable information, we introduced a novel method of data masking. Sensitive string variables are encrypted using Bloom filters, which enables calculation of similarity coefficients. For date variables, we developed special encryption procedures to handle the most common date errors. The linkage center performs probabilistic record linkage with encrypted person identifiable information and plain non-sensitive variables. RESULTS In this paper we describe step by step how to link existing health-related data using encryption methods to preserve privacy of persons in the study. CONCLUSION Privacy Preserving Probabilistic Record linkage expands record linkage facilities in settings where a unique identifier is unavailable and/or regulations restrict access to the non-unique person identifiable information needed to link existing health-related data sets. Automated pre-processing and encryption fully protect sensitive information ensuring participant confidentiality. This method is suitable not just for epidemiological research but also for any setting with similar challenges.

Quality of life in high-risk patients: comparison of transcatheter aortic valve implantation with surgical aortic valve replacement

OBJECTIVES To compare health-related quality of life (QoL) in patients undergoing transcatheter aortic valve implantation via transapical access (TA TAVI) with patients undergoing surgical aortic valve replacement (SAVR). METHODS One hundred and forty-four high-risk patients referred for aortic valve replacement underwent TAVI screening and were assigned to either TA TAVI (n = 51, age 79.7 ± 9.2 years, logistic EuroSCORE 26.5 ± 16.1%, 51% males) or SAVR (n = 93, age 81.1 ± 5.3 years, logistic EuroSCORE 12.1 ± 9.3%, 42% males) by the interdisciplinary heart team. QoL was assessed using the Short Form 36 (SF-36) Health Survey Questionnaire and the Hospital Anxiety and Depression Scale. Furthermore, current living conditions and the degree of independence at home were evaluated. RESULTS Patients undergoing TA TAVI were at higher risk as assessed by EuroSCORE (26.5 ± 16 vs. 12.1 ± 9, P < 0.001) and STS score (6.7 ± 4 vs. 4.4 ± 3, P < 0.001) compared with SAVR patients. At the 30-day follow-up, the rate of mortality was similar and amounted to 7.8% for TA TAVI and 7.5% for SAVR patients and raised to 25.5% in TA TAVI and 18.3% in SAVR patients after a follow-up period of 15 ± 10 months. Assessment of QoL revealed no differences in terms of anxiety and depression between TA TAVI and SAVR patients. The SF-36 mental health metascore was similar in both groups (65.6 ± 19 vs. 68.8 ± 22, P = 0.29), while a significant difference was observed in the physical health metascore (49.7 ± 21 vs. 62.0 ± 21, P = 0.015). After adjustment for baseline characteristics, this difference disappeared. However, every added point in the preoperative risk assessment with the STS score decreased the SF-36 physical health dimension by two raw points at the follow-up assessment. CONCLUSIONS Selected high-risk patients undergoing TAVI by using a transapical access achieve similar clinical outcomes and QoL compared with patients undergoing SAVR. Increased STS scores predict worse QoL outcomes.

Content comparison of health status measures for obesity based on the international classification of functioning, disability and health

OBJECTIVE: To compare the content covered by twelve obesity-specific health status measures using the International Classification of Functioning, Disability and Health (ICF). DESIGN: Obesity-specific health status measures were identified and then linked to the ICF separately by two trained health professionals according to standardized guidelines. The degree of agreement between health professionals was calculated by means of the kappa (kappa) statistic. Bootstrapped confidence intervals (CI) were calculated. The obesity-specific health-status measures were compared on the component and category level of the ICF. MEASUREMENTS: welve condition-specific health-status measures were identified and included in this study, namely the obesity-related problem scale, the obesity eating problems scale, the obesity-related coping and obesity-related distress questionnaire, the impact of weight on quality of life questionnaire (short version), the health-related quality of life questionnaire, the obesity adjustment survey (short form), the short specific quality of life scale, the obesity-related well-being questionnaire, the bariatric analysis and reporting outcome system, the bariatric quality of life index, the obesity and weight loss quality of life questionnaire and the weight-related symptom measure. RESULTS: In the 280 items of the eight measures, a total of 413 concepts were identified and linked to the 87 different ICF categories. The measures varied strongly in the number of concepts contained and the number of ICF categories used to map these concepts. Items on body functions varied form 12% in the obesity-related problem scale to 95% in the weight-related symptom measure. The estimated kappa coefficients ranged between 0.79 (CI: 0.72, 0.86) at the component ICFs level and 0.97 (CI: 0.93, 1.0) at the third ICF's level. CONCLUSION: The ICF proved highly useful for the content comparison of obesity-specific health-status measures. The results may provide clinicians and researchers with new insights when selecting health-status measures for clinical studies in obesity.

The KIDSCREEN-27 quality of life measure for children and adolescents: psychometric results from a cross-cultural survey in 13 European countries

OBJECTIVE: To assess the construct and criterion validity of the KIDSCREEN-27 health-related quality of life (HRQoL) questionnaire, a shorter version of the KIDSCREEN-52. METHODS: The five-dimensional KIDSCREEN-27 was tested in a sample of 22,827. For criterion validity the correlation with and the percentage explained variance of the scores of the KIDSCREEN-52 instrument were examined. Construct validity was assessed by testing a priori expected associations with other generic HRQoL measures (YQOL-S, PedsQL, CHIP), indicators of physical and mental health, and socioeconomic status. Age and gender differences were investigated. RESULTS: Correlation with corresponding scales of the KIDSCREEN-52 ranged from r = 0.63 to r = 0.96, and r2 ranged from 0.39 to 0.92. Correlations between other HRQoL questionnaires and KIDSCREEN-27 dimensions were moderate to high for those assessing similar constructs (r = 0.36 to 0.63). Statistically significant and sizeable differences between physically and mentally healthy and ill children were found in all KIDSCREEN-27 dimensions together with strong associations with psychosomatic complaints (r = -0.52). Most of the KIDSCREEN-27 dimensions showed a gradient according to socio-economic status, age and gender. CONCLUSIONS: The KIDSCREEN-27 seems to be a valid measure of HRQoL in children and adolescents. Further research is needed to assess longitudinal validity and sensitivity to change.

Feasibility of future epidemiological studies on possible health effects of mobile phone base stations

The increasing deployment of mobile communication base stations led to an increasing demand for epidemiological studies on possible health effects of radio frequency emissions. The methodological challenges of such studies have been critically evaluated by a panel of scientists in the fields of radiofrequency engineering/dosimetry and epidemiology. Strengths and weaknesses of previous studies have been identified. Dosimetric concepts and crucial aspects in exposure assessment were evaluated in terms of epidemiological studies on different types of outcomes. We conclude that in principle base station epidemiological studies are feasible. However, the exposure contributions from all relevant radio frequency sources have to be taken into account. The applied exposure assessment method should be piloted and validated. Short to medium term effects on physiology or health related quality of life are best investigated by cohort studies. For long term effects, groups with a potential for high exposure need to first be identified; for immediate effect, human laboratory studies are the preferred approach.

Assessment of quality of life in patients with uncontrolled vs. controlled acromegaly using the Acromegaly Quality of Life Questionnaire (AcroQoL)

Acromegaly is a chronic disease with an important impact on quality of life. An acromegaly disease-generated quality of life questionnaire (AcroQoL) has recently been developed. We aimed to confirm reliability, construct validity and disease-specificity of the AcroQoL questionnaire. Second, we investigated the effect of remission status on health-related quality of life (HRQoL) in patients with acromegaly.

Association of fatigue and psychological distress with quality of life in patients with a previous venous thromboembolic event

Health-related quality of life (QoL) has been associated with several social and medical conditions in patients with deep vein thrombosis (DVT) and pulmonary embolism (PE). To the best of our knowledge, there is no study investigating the relationship of QoL with psychological variables in this patient population. We assumed as a hypothesis an association between heightened levels of fatigue and psychological distress, as well as decreased QoL in patients with an objectively diagnosed venous thromboembolic event. Study participants were 205 consecutively enrolled out-patients (47.4 years, 54.6% men) with DVT and/or PE. Approximately 10 days before blood collection for thrombophilia work-up, QoL, fatigue, and psychological distress were assessed using the Short Form Health Survey (SF-12), the Multidimensional Fatigue Symptom Inventory Short Form (MFSI-SF) as well as the Hospitality Anxiety and Depression scale (HADS). After controlling for demographic and medical factors, fatigue (p < 0.01) but not psychological distress (p>0.05) was negatively associated with physical QoL, explaining 11.0% of the variance. Fatigue (p < 0.001) and psychological distress (p < 0.001) were significant predictors of mental QoL, explaining an additional 36.2% and 3.6% of the variance. Further analyses revealed that all subscales of the HADS (e.g. anxiety and depression) and of the MFSI-SF (e.g. general fatigue, physical fatigue, emotional fatigue, mental fatigue and vigor) were significant predictors of mental QoL. MFSI-SF subscales also predicted physical QoL. The findings suggest that fatigue and psychological distress substantially predict QoL in patients with a previous venous thromboembolic event above and beyond demographic factors.

Feasibility and acceptance of electronic quality of life assessment in general practice: an implementation study

Background Patients' health related quality of life (HRQoL) has rarely been systematically monitored in general practice. Electronic tools and practice training might facilitate the routine application of HRQoL questionnaires. Thorough piloting of innovative procedures is strongly recommended before the conduction of large-scale studies. Therefore, we aimed to assess i) the feasibility and acceptance of HRQoL assessment using tablet computers in general practice, ii) the perceived practical utility of HRQoL results and iii) to identify possible barriers hindering wider application of this approach. Methods Two HRQoL questionnaires (St. George's Respiratory Questionnaire SGRQ and EORTC QLQ-C30) were electronically presented on portable tablet computers. Wireless network (WLAN) integration into practice computer systems of 14 German general practices with varying infrastructure allowed automatic data exchange and the generation of a printout or a PDF file. General practitioners (GPs) and practice assistants were trained in a 1-hour course, after which they could invite patients with chronic diseases to fill in the electronic questionnaire during their waiting time. We surveyed patients, practice assistants and GPs regarding their acceptance of this tool in semi-structured telephone interviews. The number of assessments, HRQoL results and interview responses were analysed using quantitative and qualitative methods. Results Over the course of 1 year, 523 patients filled in the electronic questionnaires (1–5 times; 664 total assessments). On average, results showed specific HRQoL impairments, e.g. with respect to fatigue, pain and sleep disturbances. The number of electronic assessments varied substantially between practices. A total of 280 patients, 27 practice assistants and 17 GPs participated in the telephone interviews. Almost all GPs (16/17 = 94%; 95% CI = 73–99%), most practice assistants (19/27 = 70%; 95% CI = 50–86%) and the majority of patients (240/280 = 86%; 95% CI = 82–91%) indicated that they would welcome the use of electronic HRQoL questionnaires in the future. GPs mentioned availability of local health services (e.g. supportive, physiotherapy) (mean: 9.4 ± 1.0 SD; scale: 1 – 10), sufficient extra time (8.9 ± 1.5) and easy interpretation of HRQoL results (8.6 ± 1.6) as the most important prerequisites for their use. They believed HRQoL assessment facilitated both communication and follow up of patients' conditions. Practice assistants emphasised that this process demonstrated an extra commitment to patient centred care; patients viewed it as a tool, which contributed to the physicians' understanding of their personal condition and circumstances. Conclusion This pilot study indicates that electronic HRQoL assessment is technically feasible in general practices. It can provide clinically significant information, which can either be used in the consultation for routine care, or for research purposes. While GPs, practice assistants and patients were generally positive about the electronic procedure, several barriers (e.g. practices' lack of time and routine in HRQoL assessment) need to be overcome to enable broader application of electronic questionnaires in every day medical practice.

Valuing the Health States Associated with Chlamydia trachomatis Infections and Their Sequelae: A Systematic Review of Economic Evaluations and Primary Studies

OBJECTIVES Economic evaluations of interventions to prevent and control sexually transmitted infections such as Chlamydia trachomatis are increasingly required to present their outcomes in terms of quality-adjusted life-years using preference-based measurements of relevant health states. The objectives of this study were to critically evaluate how published cost-effectiveness studies have conceptualized and valued health states associated with chlamydia and to examine the primary evidence available to inform health state utility values (HSUVs). METHODS A systematic review was conducted, with searches of six electronic databases up to December 2012. Data on study characteristics, methods, and main results were extracted by using a standard template. RESULTS Nineteen economic evaluations of relevant interventions were included. Individual studies considered different health states and assigned different values and durations. Eleven studies cited the same source for HSUVs. Only five primary studies valued relevant health states. The methods and viewpoints adopted varied, and different values for health states were generated. CONCLUSIONS Limitations in the information available about HSUVs associated with chlamydia and its complications have implications for the robustness of economic evaluations in this area. None of the primary studies could be used without reservation to inform cost-effectiveness analyses in the United Kingdom. Future debate should consider appropriate methods for valuing health states for infectious diseases, because recommended approaches may not be suitable. Unless we adequately tackle the challenges associated with measuring and valuing health-related quality of life for patients with chlamydia and other infectious diseases, evaluating the cost-effectiveness of interventions in this area will remain problematic.

Patients with oral tumors. Part 2: Quality of life after treatment with resection prostheses. Resection prosthetics: evaluation of quality of life

In the present study, the oral health-related quality of life of 18 patients (13 men and 5 women) was evaluated using validated questionnaires as proposed by the European Organization of Research and Treatment of Cancer (EORTC). The patients belonged to a cohort of 48 patients, whose prosthetic treatment was performed during the years 2004-2007. In the course of tumor resection, 12 patients underwent graft surgery and 14 patients radiotherapy. One patient required a nasal epithesis since resection of the nose became necessary. Five patients underwent a full block resection of the mandible, and tumor resection in 3 patients resulted in a large oronasal communication. Prosthetic rehabilitation was performed in all patients, and the follow-up period with regular care covered a minimum of 3 years. Eleven patients received dental implants for better support and retention of the prostheses. In spite of compromised oral conditions, functional restrictions, and some difficulties with the prostheses, the answers to the questionnaire were quite positive. The majority judged their general health as good or even excellent. The subjective perception of the patients may contradict the objective view by the dentist. In fact, the individual patient's history and experience provide a better understanding of the impact of oral tumors on daily life. The overall assessment identified 4 items that were perceived as major problems by all patients: swallowing solid food, dry mouth, limited mouth opening, and appearance. Prosthetic rehabilitation has only a limited influence on such problems.

Adaption of cardio-respiratory balance during day-rest compared to deep sleep—An indicator for quality of life?

Heart rate and breathing rate fluctuations represent interacting physiological oscillations. These interactions are commonly studied using respiratory sinus arrhythmia (RSA) of heart rate variability (HRV) or analyzing cardiorespiratory synchronization. Earlier work has focused on a third type of relationship, the temporal ratio of respiration rate and heart rate (HRR). Each method seems to reveal a specific aspect of cardiorespiratory interaction and may be suitable for assessing states of arousal and relaxation of the organism. We used HRR in a study with 87 healthy subjects to determine the ability to relax during 5 day-resting periods in comparison to deep sleep relaxation. The degree to which a person during waking state could relax was compared to somatic complaints, health-related quality of life, anxiety and depression. Our results show, that HRR is barely connected to balance (LF/HF) in HRV, but significantly correlates to the perception of general health and mental well-being as well as to depression. If relaxation, as expressed in HRR, during day-resting is near to deep sleep relaxation, the subjects felt healthier, indicated better mental well-being and less depressive moods.

Self-esteem, coping styles, and quality of life in polish adolescents and young adults with unilateral cleft lip and palate.

Objectives : To evaluate self-esteem, coping styles, and health-related quality of life and their relationships in Polish adolescents and young adults with unilateral complete cleft lip and palate and related sex differences. Design and Participants : Self-report questionnaires measuring self-esteem (Multidimensional Self-Esteem Inventory), coping styles (Coping Inventory for Stressful Situations), and health-related quality of life (WHOQOL-BREF) were completed by 48 participants with cleft lip and palate (age, 16 to 23 years; 31 males, 17 females) and 48 controls without cleft lip and palate (age, 16 to 23 years; 28 males, 20 females) matched for age, place of residence, and socioeconomic status. Results : Regarding self-esteem, individuals with cleft lip and palate scored higher on body functioning (P < .01) and defensive self-enhancement (P < .05). Self-control showed an interaction effect: Females with cleft lip and palate scored higher than controls, but males did not differ between groups (P < .05). Males with cleft lip and palate scored lower than controls in personal power but higher in body functioning (P < .05); females showed no differences between groups. The groups did not differ with regard to coping styles or quality of life, but several correlations were found between self-esteem and coping styles, and quality of life (P < .01). Conclusions : Late adolescents and young adults with and without cleft lip and palate differed little in terms of psychological adjustment measures. The higher scores in defensive self-enhancement of individuals with cleft lip and palate suggest the need for instruments measuring social approval in psychosocial adjustment research involving this group.

Impact of dental caries and trauma on quality of life among 5- to 6-year-old children: perceptions of parents and children.

OBJECTIVE To assess the impact of dental caries and traumatic dental injuries (TDI) on the oral health-related quality of life (OHRQoL) of 5- to 6-year-olds according to both self- and parental reports. METHODS A total of 335 pairs of parents and children who sought dental screening at the Dental School, University of São Paulo, completed the Scale of Oral Health Outcomes for 5-year-old children (SOHO-5), which consists of a child self-report and a parental proxy-report version. Three calibrated examiners assessed the experience of caries according to primary teeth that were decayed, indicated for extraction due to caries, or filled (def-t). TDI were classified into uncomplicated and complicated injuries. Poisson regression models were used to associate the different clinical and sociodemographic factors to the outcome. RESULTS Overall, 74.6% of children reported an oral impact, and the corresponding estimate for parental reports was 70.5%. The mean (standard deviation) SOHO-5 scores in child self-report and parental versions were 3.32(3.22) and 5.18(6.28), respectively. In both versions, caries was associated with worse children's OHRQoL, for the total score and all SOHO-5 items (P < 0.001). In contrast, TDI did not have a negative impact on children's OHRQoL, with the exception of two items of the parental version and one item of the child self-report version. In the final multivariate adjusted models, there was a gradient in the association between caries experience and child's OHRQoL with worse SOHO-5 score at each consecutive level with more severe caries experience, for both child and parental perceptions [RR (CI 95%) = 6.37 (4.71, 8.62) and 10.81 (7.65, 15.27)], respectively. A greater family income had a positive impact on the children's OHRQoL for child and parental versions [RR (CI 95%) = 0.68 (0.49, 0.94) and 0.70 (0.54, 0.90)], respectively. CONCLUSIONS Dental caries, but not TDI, is associated with worse OHRQoL of 5- to 6-year-old children in terms of perceptions of both children and their parents. Families with higher income report better OHRQoL at this age, independent of the presence of oral diseases.

Quality of life after pulmonary embolism: validation of the French version of the PEmb-QoL questionnaire.

BackgroundThe PEmb-QoL is a validated 40-item questionnaire to quantify health-related quality of life in patients having experienced pulmonary embolism (PE). It covers six health dimensions: frequency of complaints, activities of daily living limitations, work-related problems, social limitations, intensity of complaints, and emotional complaints. Originally developed in Dutch and English, we sought to prospectively validate the psychometric properties of a French version of the PEmb-QoL.MethodsWe performed a forward and backward translation of the English version of the PEmb-QoL into French. French-speaking consecutive adult patients with an acute, objectively confirmed PE admitted to the emergency department of a Swiss university hospital between 08/2009 and 09/2011 were recruited telephonically. We used standard psychometric tests and criteria to evaluate the acceptability, reliability, and validity of the French version of the PEmb-QoL. We also performed an exploratory factor analysis.ResultsOverall, 102 patients were enrolled in the study. The French version of the PEmb-QoL showed good reliability (internal consistency, item¿total and inter-item correlations), reproducibility (test-retest reliability), and validity (convergent, discriminant) in French-speaking patients with PE. The exploratory factor analysis suggested three underlying dimensions: limitations in daily activity (items 4b-m, 5a-d), symptoms (items 1a-h and 7), and emotional complaints (items 9a-f and j).ConclusionWe successfully validated the French version of the PEmb-QoL questionnaire in patients with PE. Our results show that the PEmb-QoL is a valuable tool for assessing health-related quality of life after PE in French-speaking patients.