Professionalism in Hand Surgery: Treating the Noncompliant Patient.

Every practicing hand surgeon has had the challenging experience of treating a patient who demonstrates difficulty with, or inability to comply with medical advice. Patient noncompliance can lead to not only poor patient outcomes but also deterioration in the therapeutic relationship, physician burnout, high cost of care, and medical-legal risk. The guiding principles in the ethical practice of medicine render it important to consider noncompliance as a potentially modifiable risk factor, and every attempt should be made to work with these noncompliant patients to achieve the best possible outcomes. Data suggest that noncompliance may be affected by socioeconomic status and race; many of these patients are among the vulnerable. However, in some instances, treatment options may warrant alteration or adjustment to reflect the noncompliance of the patient. Rarely, it may be reasonable for a physician to discharge a patient from care once any urgent problems have been managed. Ethical and responsible management of a noncompliant patient requires a thoughtful and measured approach.

Non-compliance with smoke-free law in public places: a systematic review and meta-analysis of global studies.

Introduction: Non-compliance with smoke-free law is one of the determinants of untimely mortality and morbidity globally. Various studies have been conducted on non-compliance with smoke-free law in public places in different parts of the world; however, the findings are inconclusive and significantly dispersed. Moreover, there is a lack of internationally representative data, which hinders the evaluation of ongoing international activities towards smoke-free law. Therefore, this meta-analysis aimed to assess the pooled prevalence of non-compliance with smoke-free law in public places. Methods: International electronic databases, such as PubMed/MEDLINE, Science Direct, Cochrane Library, CINAHL, African Journals Online, HINARI, Semantic Scholar, google and Google Scholar were used to retrieve the relevant articles. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA) guidelines. The Higgs I2 statistics were used to determine the heterogeneity of the reviewed articles. The random-effects model with a 95% confidence interval was carried out to estimate the pooled prevalence of non-compliance. Results: A total of 23 articles with 25,573,329 study participants were included in this meta-analysis. The overall pooled prevalence of non-compliance with smoke-free law was 48.02% (95% CI: 33.87-62.17). Extreme heterogeneity was observed among the included studies (I2 = 100%; p < 0.000). The highest non-compliance with smoke-free law was noted in hotels (59.4%; 95% CI: 10.5-108.3) followed by homes (56.8%; 95% CI: 33.2-80.4), with statistically significant heterogeneity. Conclusion: As the prevalence of non-compliance with smoke-free law is high in public places, it calls for urgent intervention. High non-compliance was found in food and drinking establishments and healthcare facilities. In light of these findings, follow-up of tobacco-free legislation and creating awareness that focused on active smokers particularly in food and drinking establishments is recommended.

The interplay of psychosis and non-compliance with fatal outcome in an adult with MSUD.

Significant progress has been achieved in enhancing early outcomes for individuals with maple syrup urine disease (MSUD), a rare metabolic disorder that leads to the accumulation of branched-chain amino acids leucine, isoleucine, and valine, where leucine is known as the primary neurotoxic metabolite. Newborn screening is helpful in early diagnosis and implementation of dietary treatment, thus reducing neurological deterioration and complications in young children. However, patients face the life-long challenge of maintaining metabolic control through adherence to a strict low-leucine diet to avoid long-term consequences of chronic hyperleucinemia, which include cognitive deficits, mood disorders, and movement disorders. This case report exemplifies the complex involvement of MSUD in adult survivors. Despite presenting early in life, the patient thrived until the onset of psychiatric symptoms. The subject of this case is a 25-year-old woman with MSUD, who remained in her usual state of health until presentation to the emergency department (ED) with psychosis and altered mental status. However, due to a lack of medical records and poor communication, there was a delay in considering MSUD as a primary cause of her psychiatric symptoms. Although a genetics consultation was later arranged and efforts were made to decrease plasma leucine to the therapeutic range, these interventions proved inadequate in halting her deterioration in health. Her condition worsened within 72 h, culminating in her untimely death. This case emphasizes the comorbidity of psychiatric involvement in MSUD, which contributes to metabolic decompensation that can lead to cerebral edema and death. This case also highlights the pressing need for enhanced strategies for the acute management and long-term care of MSUD patients with psychiatric involvement, particularly in scenarios where mental disturbance could lead to noncompliance.

How could a pooled testing policy have performed in managing the early stages of the COVID-19 pandemic? Results from a simulation study.

A coordinated testing policy is an essential tool for responding to emerging epidemics, as was seen with COVID-19. However, it is very difficult to agree on the best policy when there are multiple conflicting objectives. A key objective is minimizing cost, which is why pooled testing (a method that involves pooling samples taken from multiple individuals and analyzing this with a single diagnostic test) has been suggested. In this article, we present results from an extensive and realistic simulation study comparing testing policies based on individually testing subjects with symptoms (a policy resembling the UK strategy at the start of the COVID-19 pandemic), individually testing subjects at random or pools of subjects randomly combined and tested. To compare these testing methods, a dynamic model compromised of a relationship network and an extended SEIR model is used. In contrast to most existing literature, testing capacity is considered as fixed and limited rather than unbounded. This article then explores the impact of the proportion of symptomatic infections on the expected performance of testing policies. Symptomatic testing performs better than pooled testing unless a low proportion of infections are symptomatic. Additionally, we include the novel feature for testing of non-compliance and perform a sensitivity analysis for different compliance assumptions. Our results suggest for the pooled testing scheme to be superior to testing symptomatic people individually, only a small proportion of the population ( > 10 % $$ >10\% $$ ) needs to not comply with the testing procedure.

Treatment Non-adherence Patterns Among Patients With Mental Illness: A Study From the District Mental Health Care Center in India.

INTRODUCTION: The success of any medical intervention, including mental health treatment, depends largely on patient adherence to the prescribed regimen. In psychiatric illnesses, one of the biggest problems is getting people to adhere to their treatment schedule, representing a treatment gap that increases the burdens of patients, families, communities, and countries. Globally, it has become necessary for community health organizations to actively work towards reducing this gap and treatment non-adherence. Therefore, in this study, we aimed to examine treatment non-adherence patterns among patients with mental illness. MATERIALS AND METHODS: This work used a retrospective study design and consecutive sampling. The data source was secondary data obtained from the healthcare records of patients registered in the outpatient department of the District Mental Health Care Center, India, from January 2022 to December 2022. RESULTS: Out of a total of 883 patients recruited for the study, 35.7% (n=315) were on regular follow-up over a duration of more than one year. Among patients with severe mental illness, 46% (n=46) had regular follow-ups and were compliant with therapy. About 49% of patients (n=433) discontinued their treatment after the initial contact with the therapist, with the highest rate among those with substance use disorders (77.0%; n=57). The remaining 15.3% (n=135) of recruited patients discontinued their follow-up appointments over a duration of 1 week to 12 months. Overall, 64.3% (n=568) of the recruited patients discontinued their treatment within one year. CONCLUSION: There was considerable early treatment dropout among patients with mental illness. However, this treatment discontinuation can be avoided because the individual identities of these patients are well-known to the therapist or facility, as they have had at least one interaction with the therapist. In order to improve treatment adherence, patients with mental illnesses must receive consistent support through community outreach programs, home visits, and new strategies to promote treatment compliance.

Use, failure, and non-compliance of respiratory personal protective equipment and risk of upper respiratory tract infections-A longitudinal repeated measurement study during the COVID-19 pandemic among healthcare workers in Denmark.

INTRODUCTION: Upper respiratory tract infections (URTI) are common and a common cause of sick-leave for healthcare workers, and furthermore pose a threat especially for patients susceptible to other diseases. Sufficient use of respiratory protective equipment (RPE) may protect both the workers and the patients. The COVID-19 pandemic provided a unique opportunity to study the association between use of RPE and URTI in a real-life setting. The aim of this study was to examine if failure of RPE or non-compliance with RPE guidelines increases the risk of non-COVID-19 URTI symptoms among healthcare workers. METHODS: In a longitudinal cohort study, we collected self-reported data daily on work tasks, use of RPE, and URTI symptoms among healthcare workers with patient contact in 2 Danish Regions in 2 time periods during the COVID-19 pandemic. The association between failure of RPE or non-compliance with RPE guidelines and URTI symptoms was analyzed separately by generalized linear models. Persons tested positive for severe acute respiratory syndrome coronavirus 2 were censored from the analyses. The 2 waves of data collection were analyzed separately, as there were differences in recommendations of RPE during the 2 waves. RESULTS: We found that for healthcare workers performing work tasks with a risk of transmission of viruses or bacteria, failure of RPE was associated with an increased risk of URTI symptoms, RR: 1.65[0.53-5.14] in wave 1 and RR: 1.30[0.56-3.03] in wave 2. Also non-compliance with RPE guidelines was associated with an increased risk of URTI symptoms compared to the use of RPE in wave 1, RR: 1.28[0.87-1.87] and wave 2, RR: 1.39[1.01-1.91]. Stratifying on high- versus low-risk tasks showed that the risk related to failure and non-compliance was primarily associated with high-risk tasks, although not statistically significant. DISCUSSION: The study was conducted during the COVID-19 pandemic and thus may be affected by other preventive measures in society. However, this gave the opportunity to study the use of RPE in a real-life setting, also in departments that did not previously use RPE. The circumstances in the 2 time periods of data collection differed and were analyzed separately and thus the sample size was limited and affected the precision of the estimates. CONCLUSION: Failures of RPE and non-compliance with RPE guidelines may increase the risk of URTI, compared to those who reported use of RPE as recommended. The implications of these findings are that the use of RPE to prevent URTI could be considered, especially while performing high-risk tasks where other prevention strategies are not achievable.

Underreporting of non-study cigarette use by study participants confounds the interpretation of results from ambulatory clinical trial of reduced nicotine cigarettes.

BACKGROUND: As part of its comprehensive plan to significantly reduce the harm from tobacco products, the US Food and Drug Administration is establishing a product standard to lower nicotine in conventional cigarettes to make them "minimally addictive or non-addictive". Many clinical studies have investigated the potential impact of such a standard on smoking behavior and exposure to cigarette constituents. These ambulatory studies required participants who smoke to switch to reduced nicotine study cigarettes. In contrast to clinical trials on pharmaceuticals or medical devices, participants had ready access to non-study conventional nicotine cigarettes and high rates of non-study cigarette use were consistently reported. The magnitude of non-compliance, which could impact the interpretation of the study results, was not adequately assessed in these trials. METHODS: We conducted a secondary analysis of data from a large, randomized trial of reduced nicotine cigarettes with 840 participants to estimate the magnitude of non-compliance, i.e., the average number of non-study cigarettes smoked per day by study participants assigned to reduced nicotine cigarettes. Individual participants' non-study cigarette use was estimated based on his/her urinary total nicotine equivalent level, the nicotine content of the study cigarette assigned and the self-reported number of cigarettes smoked, using a previously published method. RESULTS: Our analysis showed that (1) there is a large variation in the number of non-study cigarettes smoked by participants within each group (coefficient of variation 90-232%); (2) participants in reduced nicotine cigarette groups underreported their mean number of non-study cigarettes smoked per day by 85-91%; and (3) the biochemical-based estimates indicate no reduction in the mean number of total cigarettes smoked per day for any group assigned to reduced nicotine cigarettes after accounting for non-study cigarettes. CONCLUSIONS: High levels of non-compliance, in both the rate and magnitude of non-study cigarette use, are common in ambulatory reduced nicotine cigarette trials where participants have access to conventional nicotine non-study cigarettes. The potential impact of high non-compliance on study outcomes should be considered when interpreting the results from such ambulatory studies.

Risk factors for non-participation in ivermectin and dihydroartemisinin-piperaquine mass drug administration for malaria control in the MASSIV trial.

BACKGROUND: Mass Drug Administration (MDA) has become a mainstay for the control of several diseases over the last two decades. Successful implementation of MDA programmes requires community participation and can be threatened by systematic non-participation. Such concerns are particularly pertinent for MDA programmes against malaria, as they require multi-day treatment over several consecutive months. Factors associated with non-participation to the MDA campaign with ivermectin (IVM) and dihydroartemisinin-piperaquine (DHP) implemented within the MASSIV cluster randomized trial were determined. METHODS: Coverage data was extracted from the MASSIV trial study database, with every datapoint being a directly observed therapy (DOT). A complete month of MDA was classified as receiving all three daily doses of treatment. For both ivermectin and DHP, ordinal logistic regression was used to identify individual and household level variables associated with non-participation. RESULTS: For ivermectin, 51.5% of eligible participants received all 3 months of treatment while 30.7% received either one or two complete months. For DHP, 56.7% of eligible participants received all 3 months of treatment and 30.5% received either one or two complete months. Children aged 5-15 years and adults aged more than 50 years were more likely to receive at least one complete month of MDA than working age adults, both for ivermectin (aOR 4.3, 95% CI 3.51-5.28 and aOR of 2.26, 95% CI 1.75-2.95) and DHP (aOR 2.47, 95%CI 2.02-3.02 and aOR 1.33, 95%CI 1.01-1.35), respectively. Members of households where the head received a complete month of MDA were more likely to themselves have received a complete month of MDA, both for ivermectin (aOR 1.71, 95%CI 1.35-2.14) and for DHP (aOR 1.64, 95%CI 1.33-2.04). CONCLUSION: Personal and household-level variables were associated with participation in the MDA programme for malaria control. Specific strategies to (increase participation amongst some groups may be important to ensure maximum impact of MDA strategies in achieving malaria elimination. TRIAL REGISTRATION: The MASSIV trial is registered under NCT03576313.

Non-compliance of Spectacle Wear in School-Going Children With Refractive Errors.

Background Uncorrected refractive errors are the most common cause of avoidable visual impairment in children worldwide. The school screening of refractive errors is one of the most important initiatives outlined in WHO Vision 2020 targets for control of avoidable visual impairment in children. However, the benefit depends on the compliance of the spectacle worn by children. Objective To determine non-compliance of spectacle wear and its predisposing factors among school-going children in Lahore, Pakistan. Methods This cross-sectional analytical study was conducted among 200 school-going children (5-16 years), with spectacle prescription for at least the last six months studying in primary and secondary schools of Lahore, by using convenience sampling. We collected data with the help of a standardized, self-administered, close-ended questionnaire determining age, gender, class, and non-compliance and its reasons. Data were subjected to statistical evaluation using Statistical Product and Service Solutions (SPSS, version 26; IBM SPSS Statistics for Windows, Armonk, NY), and a chi-square test was applied to determine the statistical significance. p-value 0.05 was considered significant. Results Of the 200 children, 42 were boys, and 158 were girls, with a mean age of 12 years with a standard deviation of 2.6. The proportion of spectacle wear non-compliance was 19.5% (n=39). Children with non-compliance were more likely in the age group of 14-16 years (n=20{51.3%}; p=0.039). The main reasons for non-compliance were dislike to wear spectacles (28.2%), broken spectacles (23.1%), spectacles causing headache (20.5%), spectacles lost and parents' disapproval (20.5%), and peer pressure/teasing (15.4%). Significant difficulties faced while wearing spectacles were pressure on the nose due to worn-out nose pads (36.4%), pressure on ears causing pain in the temple and headache (34.1%), repeated cleaning of spectacles (29.5%), heavy spectacles (18.2%), excessive glare and pain in the eyes (12.5%), and improper fitting of spectacles (11.4%). Conclusions We found that non-compliance was more significant in school-going children aged 14-16 years and girls. The main reasons were unlikeness to wear, broken spectacles, headache, and spectacles lost. School children were not compliant because of many issues that should be addressed, and this information will be used for better eye care in school-going children with refractive errors.

Evaluation of non-conformities in the drafting of bulletins for urine cytobacteriological examinations at Sikasso Hospital (Mali).

Background: Non-compliance in the drafting of examination bulletins makes it difficult to perform them and interpret the results. With the aim of continuously improving laboratory services and guaranteeing the quality of urine cytobacteriological examination (ECBU) results, we initiated this study to evaluate non-compliance in the drafting of ECBU reports. Materials and methods: This was a retrospective descriptive cross-sectional study which focused on non-compliance in the drafting of ECBU reports analysed in the laboratory from January to December 2022. Results: During the study period, we collected 383 non-compliant ECBU reports out of 672, with a frequency of 56.99%. Non-compliances were related to age (2.68%), profession (24.40%), clinical information (6.70%) and residence (52.08%). The majority of non-compliant reports came from the medicine (35.51%) and urology (25.85%) departments. Conclusion: The high frequency of non-compliance is a cause for concern and is of concern to all prescribers in this hospital.

Principal stratification analysis of noncompliance with time-to-event outcomes.

Post-randomization events, also known as intercurrent events, such as treatment noncompliance and censoring due to a terminal event, are common in clinical trials. Principal stratification is a framework for causal inference in the presence of intercurrent events. The existing literature on principal stratification lacks generally applicable and accessible methods for time-to-event outcomes. In this paper, we focus on the noncompliance setting. We specify 2 causal estimands for time-to-event outcomes in principal stratification and provide a nonparametric identification formula. For estimation, we adopt the latent mixture modeling approach and illustrate the general strategy with a mixture of Bayesian parametric Weibull-Cox proportional hazards model for the outcome. We utilize the Stan programming language to obtain automatic posterior sampling of the model parameters. We provide analytical forms of the causal estimands as functions of the model parameters and an alternative numerical method when analytical forms are not available. We apply the proposed method to the ADAPTABLE (Aspirin Dosing: A Patient-Centric Trial Assessing Benefits and Long-Term Effectiveness) trial to evaluate the causal effect of taking 81 versus 325 mg aspirin on the risk of major adverse cardiovascular events. We develop the corresponding R package PStrata.

Marshall Joffe's Contributions to Causal Inference, Biostatistics, and Epidemiology.

We pay tribute to Marshall Joffe, PhD, and his substantial contributions to the field of causal inference with focus in biostatistics and epidemiology. By compiling narratives written by us, his colleagues, we not only present highlights of Marshall's research and their significance for causal inference but also offer a portrayal of Marshall's personal accomplishments and character. Our discussion of Marshall's research notably includes (but is not limited to) handling of posttreatment variables such as noncompliance, employing G-estimation for treatment effects on failure-time outcomes, estimating effects of time-varying exposures subject to time-dependent confounding, and developing a causal framework for case-control studies. We also provide a description of some of Marshall's unpublished work, which is accompanied by a bonus anecdote. We discuss future research directions related to Marshall's research. While Marshall's impact in causal inference and the world outside of it cannot be wholly captured by our words, we hope nonetheless to present some of what he has done for our field and what he has meant to us and to his loved ones.

A complicated presentation of vertebral coccidioidomycosis dissemination: A case report and discussion.

Coccidioidomycosis, also known as San Joaquin Valley fever, is an illness caused by the dimorphic fungus Coccidioides. Coccidioidomycosis is endemic to desert regions of the Western Hemisphere, including California, Arizona, Utah, Nevada, and New Mexico. We report a case of disseminated coccidioidomycosis in a 42-year-old male. Months after an upper respiratory infection of unidentified origin, the patient began experiencing back pain. The persistence of the back pain prompted MRI and CT imaging, which revealed lytic lesions. His clinical and radiological presentation mimicked, and was originally approached, as if it were a malignancy. Metastasis or multiple myeloma were considered the most likely differential diagnoses. As a result, the patient underwent surgical exploration. Pathology results indicated the presence of a fungal infection, without evidence of malignancy. PCR confirmed the diagnosis of coccidioidomycosis. The patient began treatment with fluconazole 800 mg daily and is anticipated to receive antifungal treatment for an indefinite period.

Association between missed appointments and hospitalization for child physical abuse.

Missed cases of child physical abuse (CPA) persist despite known risk factors. Prior studies have not evaluated missed medical appointments as a risk factor for CPA. The objective of this study was to determine if an association exists between missed appointments and hospitalization for CPA. We conducted a 20-year, single health system, retrospective chart review of hospitalized patients ≤36 months of age meeting International Classification of Diseases (ICD) 9/10 criteria for CPA with ≥1 scheduled appointment in our system prior to their admission. Cases were categorized as definite CPA, high likelihood, or no concern for CPA/unable to be determined. Cases identified as definite or high likelihood of CPA were matched (5:1) with controls based on age, distance to primary care provider's (PCP's) office, sex, prior hospitalization, and race. Missed appointments were compared between cases (n = 146) and controls (n = 730). A significant difference was identified between cases and controls (26 % vs 9 %, p < 0.001) for the median proportion of missed appointments. After adjusting for matched and significant covariates, there was a 3 % increase in a patient's odds of admission for CPA for every 1 % increase in missed appointments. We found an association between missed appointments and future admission for CPA. This finding has potential to assist clinicians with CPA risk stratification and future child abuse research. Limitations include single healthcare system, ICD criteria determined by research team, and narrow definition of definite CPA.

A systematic review of simulation studies which compare existing statistical methods to account for non-compliance in randomised controlled trials.

INTRODUCTION: Non-compliance is a common challenge for researchers and may reduce the power of an intention-to-treat analysis. Whilst a per protocol approach attempts to deal with this issue, it can result in biased estimates. Several methods to resolve this issue have been identified in previous reviews, but there is limited evidence supporting their use. This review aimed to identify simulation studies which compare such methods, assess the extent to which certain methods have been investigated and determine their performance under various scenarios. METHODS: A systematic search of several electronic databases including MEDLINE and Scopus was carried out from conception to 30th November 2022. Included papers were published in a peer-reviewed journal, readily available in the English language and focused on comparing relevant methods in a superiority randomised controlled trial under a simulation study. Articles were screened using these criteria and a predetermined extraction form used to identify relevant information. A quality assessment appraised the risk of bias in individual studies. Extracted data was synthesised using tables, figures and a narrative summary. Both screening and data extraction were performed by two independent reviewers with disagreements resolved by consensus. RESULTS: Of 2325 papers identified, 267 full texts were screened and 17 studies finally included. Twelve methods were identified across papers. Instrumental variable methods were commonly considered, but many authors found them to be biased in some settings. Non-compliance was generally assumed to be all-or-nothing and only occurring in the intervention group, although some methods considered it as time-varying. Simulation studies commonly varied the level and type of non-compliance and factors such as effect size and strength of confounding. The quality of papers was generally good, although some lacked detail and justification. Therefore, their conclusions were deemed to be less reliable. CONCLUSIONS: It is common for papers to consider instrumental variable methods but more studies are needed that consider G-methods and compare a wide range of methods in realistic scenarios. It is difficult to make conclusions about the best method to deal with non-compliance due to a limited body of evidence and the difficulty in combining results from independent simulation studies. PROSPERO REGISTRATION NUMBER: CRD42022370910.

Errors in Metered Dose Inhaler Use Amongst Pediatric Asthma Patients.

Purpose: The aim of this paper is to use easily accessible smartphones as a straightforward means for physicians to objectively check Medical Device Inhaler (MDI) technique, without the need for additional devices. Additionally, we seek to assess the frequency of inhaler technique errors and their impact on asthma control. Patients and Methods: Thirty-two children between the ages of 5 and 18 receiving asthma therapy through MDIs were included. Three surveys were administered to all participants to gauge device history, asthma control, and patient characteristics. Patient technique was scored using inhaler audio signals recorded with a smartphone. For subjects that were able, forced oscillation technique (FOT) was performed during tidal breathing conditions before and after corticosteroid administration. Results: 81% (25/31) of participants used their MDIs incorrectly with the most common errors being rapid shallow breathing, inadequate breath-holding, and excessive actuations. Poor inhaler technique correlated with poorly controlled asthma symptoms. Conclusion: The use of smartphone recordings can a convenient way to evaluate technique errors and could allow patients to demonstrate and refine their technique and usage without a doctor's visit, ensuring proper technique and enhancing treatment effectiveness.

Effects of Adjusting for Instrumental Variables on the Bias and Precision of Propensity Score Weighted Estimators: Analysis Under Complete, Near, and No Positivity Violations.

Purpose: To demonstrate that using an instrumental variable (IV) with monotonicity reduces the accuracy of propensity score (PS) weighted estimators for the average treatment effect (ATE). Methods: Monotonicity in the relationship between a binary IV and a binary treatment variable is an important assumption to identify the ATE for compliers who would only take treatment when encouraged by the IV. We perform theoretical and numerical investigations to study the impact of using the IV that satisfies monotonicity on the PS of treatment in terms of the positivity assumption, which requires that the PS be strictly between 0 and 1, and the accuracy of PS weighted estimators. Two versions of monotonicity that result in one-sided or two-sided noncompliance are considered. Results: The PS adjusting for the IV always violates the positivity assumption when noncompliance occurs in one direction (one-sided noncompliance) and is more extreme than without the IV under two-sided noncompliance. These results are valid if the probability of being encouraged to get treatment and the compliance score, the probability of being a complier, are strictly between 0 and 1. Conclusion: Using a binary IV with monotonicity as a covariate for the PS model makes the estimated PSs unnecessarily extreme, reducing the accuracy of the PS weighted estimators.

Instrumental variable analysis for cost outcome: Application to the effect of primary care visit on medical cost among low-income adults.

Medical cost data often consist of zero values as well as extremely right-skewed positive values. A two-part model is a popular choice for analyzing medical cost data, where the first part models the probability of a positive cost using logistic regression and the second part models the positive cost using a lognormal or Gamma distribution. To address the unmeasured confounding in studies on cost outcome under two-part models, two instrumental variable (IV) methods, two-stage residual inclusion (2SRI) and two-stage prediction substitution (2SPS) are widely applied. However, previous literature demonstrated that both the 2SRI and the 2SPS could fail to consistently estimate the causal effect among compliers under standard IV assumptions for binary and survival outcomes. Our simulation studies confirmed that it continued to be the case for a two-part model, which is another nonlinear model. In this article, we develop a model-based IV approach, Instrumental Variable with Two-Part model (IV2P), to obtain a consistent estimate of the causal effect among compliers for cost outcome under standard IV assumptions. In addition, we develop sensitivity analysis approaches to allow the evaluation of the sensitivity of the causal conclusions to potential quantified violations of the exclusion restriction assumption and the randomization of IV assumption. We apply our method to a randomized cash incentive study to evaluate the effect of a primary care visit on medical cost among low-income adults newly covered by a primary care program.

Non-Adherence with Physiotherapeutic Rehabilitation-A Cross-Cultural Adaption of Compliance Parameters into German.

BACKGROUND: Compliance with rehabilitative physiotherapeutic measures leads to an improvement in outcomes in patients suffering from a variety of musculoskeletal conditions. To date, a tool for assessing the parameters that lead to non-adherence to physical therapy does not exist in the German language. The objective of this paper is to cross-culturally adapt a non-compliance questionnaire to German. METHODS: In reference to the "Guidelines for the Process of Cross-Cultural Adaption of Self-Reported Measures", the questionnaire was translated into German followed by a back-translation into the original language. An expert committee met and refined the pre-final version. A preliminary version was handed out to patients for evaluation of the quality of the resulting German version. RESULTS: After the forward- and back-translation of the questionnaire, some discrepancies were discovered between the translators on the one hand and between the back-translations and the original document on the other. The statistical analysis showed satisfactory results regarding the quality of the questionnaire. CONCLUSION: The translation and adaption of the items proved to have a high degree of reliability. The German version will be made available for German-speaking researchers and used for evaluating a mobile-application-based physical therapy regimen by the authors of the paper.