Rates of price disclosure associated with the surgical treatment of early-stage breast cancer one year after implementation of federal regulations.

PURPOSE: Mastectomy, breast reconstruction (BR) and breast conserving therapy (BCT) are core components of the treatment paradigm for early-stage disease but are differentially associated with significant financial burdens. Given recent price transparency regulations, we sought to characterize rates of disclosure for breast cancer-related surgery, including mastectomy, BCT, and BR (oncoplastic reconstruction, implant, pedicled flap and free flap) and identify associated factors. METHODS: For this cross-sectional analysis, cost reports were obtained from the Turquoise Health price transparency platform for all U.S. hospitals meeting national accreditation standards for breast cancer care. The Healthcare Cost Report Information System was used to collect facility-specific data. Addresses were geocoded to identify hospital referral and census regions while data from CMS was also used to identify the geographic practice cost index. We leveraged a Poisson regression model and relevant Medicare billing codes to analyze factors associated with price disclosure and the availability of an OOP price estimator. RESULTS: Of 447 identified hospitals, 221 (49.4%) disclosed prices for mastectomy and 188 42.1%) disclosed prices for both mastectomy and some form of reconstruction including oncoplastic reduction (n = 184, 97.9%), implants (n = 187, 99.5%), pedicled flaps (n = 89, 47.3%), and free flaps (n = 81, 43.1%). Non-profit status and increased market competition were associated with price nondisclosure. 121 hospitals (27.1%) had an out-of-pocket price estimator that included at least one breast surgery. CONCLUSIONS: Most eligible hospitals did not disclose prices for breast cancer surgery. Distinct hospital characteristics were associated with price disclosure. Breast cancer patients face persistent difficulty in accessing costs.

Local practice variations and payer differences underlie state-wide disparities in oncoplastic breast surgery.

BACKGROUND: Little is known about disparities in oncoplastic breast surgery delivery. METHODS: The Massachusetts All-Payer Claims Database was queried for patients who received lumpectomy for a diagnosis of breast cancer. Oncoplastic surgery was defined as adjacent tissue transfer, complex trunk repair, reduction mammoplasty, mastopexy, flap-based reconstruction, prosthesis insertion, or unspecified breast reconstruction after lumpectomy. RESULTS: We identified 18 748 patients who underwent lumpectomy between 2016 and 2020. Among those, 3140 patients underwent immediate oncoplastic surgery and 436 patients underwent delayed oncoplastic surgery. Eighty-one percent of patients who underwent oncoplastic surgery did so in the same county as they underwent a lumpectomy. However, the relative frequency of oncoplastic surgery varied significantly among counties. In multivariable regression, public insurance status (odds ratio: 0.87, 95% confidence interval: 0.80-0.95, p = 0.002) was associated with lower odds of undergoing oncoplastic surgery, even after adjusting for macromastia, other comorbidities, and county of lumpectomy. Average payments for lumpectomy with oncoplastic surgery were more than twice as high from private insurers ($840 vs. $1942, p < 0.001). CONCLUSION: Disparities in the receipt of oncoplastic surgery were related to differences in local practice patterns and the type of insurance patients held. Expanding services across counties and considering billing reform may help reduce these disparities.

SurvdigitizeR: an algorithm for automated survival curve digitization.

BACKGROUND: Decision analytic models and meta-analyses often rely on survival probabilities that are digitized from published Kaplan-Meier (KM) curves. However, manually extracting these probabilities from KM curves is time-consuming, expensive, and error-prone. We developed an efficient and accurate algorithm that automates extraction of survival probabilities from KM curves. METHODS: The automated digitization algorithm processes images from a JPG or PNG format, converts them in their hue, saturation, and lightness scale and uses optical character recognition to detect axis location and labels. It also uses a k-medoids clustering algorithm to separate multiple overlapping curves on the same figure. To validate performance, we generated survival plots form random time-to-event data from a sample size of 25, 50, 150, and 250, 1000 individuals split into 1,2, or 3 treatment arms. We assumed an exponential distribution and applied random censoring. We compared automated digitization and manual digitization performed by well-trained researchers. We calculated the root mean squared error (RMSE) at 100-time points for both methods. The algorithm's performance was also evaluated by Bland-Altman analysis for the agreement between automated and manual digitization on a real-world set of published KM curves. RESULTS: The automated digitizer accurately identified survival probabilities over time in the simulated KM curves. The average RMSE for automated digitization was 0.012, while manual digitization had an average RMSE of 0.014. Its performance was negatively correlated with the number of curves in a figure and the presence of censoring markers. In real-world scenarios, automated digitization and manual digitization showed very close agreement. CONCLUSIONS: The algorithm streamlines the digitization process and requires minimal user input. It effectively digitized KM curves in simulated and real-world scenarios, demonstrating accuracy comparable to conventional manual digitization. The algorithm has been developed as an open-source R package and as a Shiny application and is available on GitHub: https://github.com/Pechli-Lab/SurvdigitizeR and https://pechlilab.shinyapps.io/SurvdigitizeR/ .

Effects of dexamethasone on opioid consumption in pediatric tonsillectomy: a systematic review with meta-analysis.

PURPOSE: Tonsillectomy is one of the most common ambulatory procedures performed in children worldwide, with around 40,000 procedures performed in Canada every year. Although a prior systematic review indicated a clear role for dexamethasone as an analgesic adjunct, the quantity effect on opioid consumption is unknown. In the current systematic review with meta-analysis, we hypothesized that the use of dexamethasone reduces perioperative opioid consumption in pediatric tonsillectomy but does not increase rates of postoperative hemorrhage. SOURCE: We systemically searched MEDLINE, Embase, Cochrane Databases, and Web of Science from inception to 23 April 2024. Randomized controlled trials that compared intravenous dexamethasone to placebo in pediatric tonsillectomy were included in the study. The primary outcome was perioperative opioid consumption, and the secondary outcomes included the incidence of postoperative hemorrhage. We used a random effects meta-analysis to compute the mean difference (MD) or risk ratio (RR) with 95% confidence interval (CI) for each outcome. PRINCIPAL FINDINGS: Of the 1,329 studies identified in the search, we included 16 in the final analysis. Intravenous dexamethasone administration significantly reduced opioid consumption (MD, -0.11 mg·kg-1 oral morphine equivalent; 95% CI, -0.22 to -0.01) without increasing the incidence of readmission (RR, 0.69; 95% CI, 0.28 to 1.67) or reoperation due to postoperative hemorrhage (RR, 3.67; 95% CI, 0.79 to 17.1). CONCLUSIONS: Intravenous dexamethasone reduced perioperative opioid consumption in pediatric tonsillectomy without increasing the incidence of postoperative hemorrhage. STUDY REGISTRATION: PROSPERO ( CRD42023440949 ); first submitted 4 September 2023.

RéSUMé: OBJECTIF: L'amygdalectomie est l'une des interventions ambulatoires les plus courantes chez les enfants dans le monde, avec environ 40 000 interventions réalisées au Canada chaque année. Bien qu'une revue systématique antérieure ait clairement indiqué le rôle de la dexaméthasone en tant qu'adjuvant analgésique, son effet quantitatif sur la consommation d'opioïdes est inconnu. Dans la présente revue systématique avec méta-analyse, nous avons émis l'hypothèse que l'utilisation de la dexaméthasone réduirait la consommation périopératoire d'opioïdes lors des cas d'amygdalectomie pédiatrique sans augmenter les taux d'hémorragie postopératoire. SOURCES: Nous avons effectué des recherches systématiques dans les bases de données MEDLINE, Embase, Cochrane et Web of Science depuis leur création jusqu'au 23 avril 2024. Nous avons inclus les études randomisées contrôlées comparant la dexaméthasone intraveineuse à un placebo dans les cas d'amygdalectomie pédiatrique. Le critère d'évaluation principal était la consommation périopératoire d'opioïdes, et les critères d'évaluation secondaires comprenaient l'incidence d'hémorragie postopératoire. Nous avons utilisé une méta-analyse à effets aléatoires pour calculer la différence moyenne (DM) ou le risque relatif (RR) avec un intervalle de confiance (IC) à 95 % pour chaque critère d'évaluation. CONSTATATIONS PRINCIPALES: Sur les 1329 études identifiées dans la recherche, nous en avons inclus 16 dans l'analyse finale. L'administration intraveineuse de dexaméthasone a permis de réduire significativement la consommation d'opioïdes (DM, −0,11 mg·kg−1 en équivalent oral de morphine; IC 95 %, −0,22 à −0,01) sans augmenter l'incidence de réadmission (RR, 0,69; IC 95 %, 0,28 à 1,67) ou de réopération due à une hémorragie postopératoire (RR, 3,67; IC à 95 %, 0,79 à 17,1). CONCLUSION: La dexaméthasone par voie intraveineuse a réduit la consommation périopératoire d'opioïdes dans les cas d'amygdalectomie pédiatrique, sans augmenter l'incidence d'hémorragie postopératoire. ENREGISTREMENT DE L'éTUDE: PROSPERO ( CRD42023440949 ); première soumission le 4 septembre 2023.

Geographic Disparities and Payment Variation for Immediate Lymphatic Reconstruction in Massachusetts.

BACKGROUND: Little is known about practice patterns and payments for immediate lymphatic reconstruction (ILR). This study aims to evaluate trends in ILR delivery and billing practices. METHODS: We queried the Massachusetts All-Payer Claims Database between 2016 and 2020 for patients who underwent lumpectomy or mastectomy with axillary lymph node dissection for oncologic indications. We further identified patients who underwent lymphovenous bypass on the same date as tumor resection. We used ZIP code data to analyze the geographic distribution of ILR procedures and calculated physician payments for these procedures, adjusting for inflation. We used multivariable logistic regression to identify variables, which predicted receipt of ILR. RESULTS: In total, 2862 patients underwent axillary lymph node dissection over the study period. Of these, 53 patients underwent ILR. Patients who underwent ILR were younger (55.1 vs 59.3 years, P = 0.023). There were no significant differences in obesity, diabetes, or smoking history between the two groups. A greater percentage of patients who underwent ILR had radiation (83% vs 67%, P = 0.027). In multivariable regression, patients residing in a county neighboring Boston had 3.32-fold higher odds of undergoing ILR (95% confidence interval: 1.76-6.25; P < 0.001), while obesity, radiation therapy, and taxane-based chemotherapy were not significant predictors. Payments for ILR varied widely. CONCLUSIONS: In Massachusetts, patients were more likely to undergo ILR if they resided near Boston. Thus, many patients with the highest known risk for breast cancer-related lymphedema may face barriers accessing ILR. Greater awareness about referring high-risk patients to plastic surgeons is needed.

Outcomes of Dermal Regeneration Templates in Irradiated and Nonirradiated Scalp Defects.

OBJECTIVES: Dermal regeneration templates (DRTs) are frequently used to treat scalp defects. The aim was to compare the time course of healing for DRTs in scalp defects with and without preoperative radiation. METHODS: The authors conducted a retrospective cohort study of DRT-based scalp reconstruction at 2 academic medical centers between 2013 and 2022. Information was collected on demographic variables, comorbidities, medication use, history of radiation, and DRT outcomes. The primary outcome was DRT loss, defined as exposed calvarium or DRT detachment based on postoperative follow-up documentation. Kaplan-Meier survival analysis and multivariable Cox proportional-hazard regressions were used to compare DRT loss in irradiated and nonirradiated defects. Multivariable logistic regressions were used to compare 30-day postoperative complications (infection, hematoma, or seroma) in irradiated and nonirradiated defects. RESULTS: In total, 158 cases were included. Twenty-eight (18%) patients had a preoperative history of radiation to the scalp. The mean follow-up time after DRT placement was 2.6 months (SD: 4.5 mo). The estimated probability of DRT survival at 2 months was 91% (95% CI: 83%-100%) in nonirradiated patients and 65% (95% CI: 48%-88%) in irradiated patients. In the 55 patients with a bony wound base, preoperative head radiation was associated with a higher likelihood of DRT loss (hazard ratio: 11). Half the irradiated defects experienced uncomplicated total wound closure using Integra Wound Matrix Dressing with or without second-stage reconstruction. CONCLUSIONS: Dermal regeneration template can offer durable coverage in nonirradiated scalp defects. Although DRT loss is more likely in irradiated scalp defects, successful DRT-based reconstruction is possible in select cases.

The Use of Unlisted Billing Codes for Microsurgical Breast Reconstruction and Implications for Code Consolidation.

BACKGROUND: Private insurers have considered consolidating the billing codes presently available for microvascular breast reconstruction. There is a need to understand how these different codes are currently distributed and used to help inform how coding consolidation may impact patients and providers. METHODS: Using the Massachusetts All-Payer Claims Database between 2016 and 2020, patients who underwent microsurgical breast reconstruction following mastectomy for cancer-related indications were identified. Multivariable logistic regression was used to test whether an S2068 claim was associated with insurance type and median household income by patient ZIP code. The ratio of S2068 to CPT19364 claims for privately insured patients was calculated for providers practicing in each county. Total payments for professional fees were compared between billing codes. RESULTS: There were 272 claims for S2068 and 209 claims for CPT19364. An S2068 claim was associated with age < 45 years (OR: 1.89, 95% CI: 1.11-3.20, p = 0.019), more affluent ZIP codes (OR: 1.11, 95% CI: 1.03-1.19, p = 0.004), and private insurance (OR: 16.13, 95% CI: 7.81-33.33, p < 0.001). Median total payments from private insurers were 101% higher for S2068 than for CPT19364. In all but two counties (Worcester and Hampshire), the S-code was used more frequently than CPT19364 for their privately insured patients. CONCLUSION: Coding practices for microsurgical breast reconstruction lacked uniformity in Massachusetts, and payments differed greatly between S2068 and CPT19364. Patients from more affluent towns were more likely to have S-code claims. Coding consolidation could impact access, as the majority of providers in Massachusetts might need to adapt their practices if the S-code were discontinued.

Using multi-level regression to determine associations and estimate causes and effects in clinical anesthesia due to patient, practitioner and hospital or health system practice variability.

In this research methods tutorial of clinical anesthesia, we will explore techniques to estimate the influence of a myriad of factors on patient outcomes. Big data that contain information on patients, treated by individual anesthesiologists and surgical teams, at different hospitals, have an inherent multi-level data structure (Fig. 1). While researchers often attempt to determine the association between patient factors and outcomes, that does not provide clinicians with the whole story. Patient care is clustered together according to clinicians and hospitals where they receive treatment. Therefore, multi-level regression models are needed to validly estimate the influence of each factor at each level. In addition, we will explore how to estimate the influence that variability-for example, one anesthesiologist deciding to do one thing, while another takes a different approach-has on outcomes for patients, using the intra-class correlation coefficient for continuous outcomes and the median odds ratio for binary outcomes. From this tutorial, you should acquire a clearer understanding of how to perform and interpret multi-level regression modeling and estimate the influence of variable clinical practices on patient outcomes in order to answer common but complex clinical questions. Fig. 1 Infographics.

Uncinate Duct Dilatation Predicts Additional Risk for High-Grade Dysplasia or Invasive Carcinoma Among Fukuoka-Positive Intraductal Papillary Mucinous Neoplasms.

OBJECTIVE: To determine whether uncinate duct dilatation (UDD) increases the risk of high-grade dysplasia or invasive carcinoma (HGD/IC) in Fukuoka-positive intraductal papillary mucinous neoplasms (IPMNs). BACKGROUND: Though classified as a branch duct, the uncinate duct is the primary duct of the pancreatic ventral anlage. We hypothesized that UDD, like main duct dilatation, confers additional risk for HGD/IC. METHODS: A total of 467 patients met inclusion criteria in a retrospective cohort study of surgically resected IPMNs at the Massachusetts General Hospital. We used multivariable logistic regression to analyze the association between UDD (defined as ≥4 mm) and HGD/IC, controlling for Fukuoka risk criteria. In a secondary analysis, the modeling was repeated in the 194 patients with dorsal branch duct IPMNs (BD-IPMNs) in the pancreatic neck, body, or tail. RESULTS: Mean age at surgery was 70, and 229 (49%) patients were female. In total, 267 (57%) patients had only worrisome features and 200 (43%) had at least 1 high-risk feature. UDD was present in 164 (35%) patients, of whom 118 (73%) had HGD/IC. On multivariable analysis, UDD increased the odds of HGD/IC by 2.8-fold, even while controlling for Fukuoka risk factors (95% CI: 1.8-4.4, P <0.001). Prevalence of HGD/IC in all patients with UDD was 73%, compared with 74% in patients with high-risk stigmata and 73% in patients with main duct IPMNs. In the secondary analysis, UDD increased the odds of HGD/IC by 3.2-fold in patients with dorsal BD-IPMNs (95% CI: 1.3-7.7, P =0.010). CONCLUSIONS: UDD confers additional risk for HGD/IC unaccounted for by current Fukuoka criteria. Further research can extend this study to Fukuoka-negative patients, including unresected patients.

Knowledge of Oral Cancer Amongst Dental Patients Attending Public Clinics in South East Queensland, Australia.

Patient knowledge of risk factors, signs and symptoms associated with oral cancers is crucial for increasing the likelihood of patient presentation for opportunistic screening and reducing delay in patient appraisal for early detection. This study aimed to assess the knowledge of oral cancer and to ascertain socio-demographic factors that influence knowledge amongst adult dental patients attending public clinics in Brisbane, Australia. A convenience sample of 213 adult dental patients who attended the Herston and Stafford public health clinics in Brisbane, Australia, between July and August 2019 participated in the self-administered questionnaire. Multivariate analyses were performed to identify predictors for oral cancer knowledge. Patients were well informed of smoking as a risk factor (n = 135; 84.4%), whereas only 53.8% (n = 82) of participants agreed that heavy alcohol consumption was a risk factor. A larger proportion of participants identified difficulty of moving the tongue (n = 79; 49.4%) and pain on swallowing (n = 72; 45.0%) compared to the proportion who identified fixed red patches (n = 61; 38.1%) and fixed white patches (n = 57; 35.6%) as a sign or symptom. Education level and gender were significant knowledge predictors for alcohol (p = 0.01), old age (p = 0.008) and family history (p = 0.004) as a risk factors for oral cancer. Those with a family history of cancer were more likely to identify a red patch (p = 0.02), bleeding gums (p = 0.001) and altered sensation (p = 0.023) as a sign or symptom of oral cancer. Overall, patient knowledge was greater for risk factors than for signs and symptoms for oral cancer. Symptoms associated with later stages of cancer were recognised by a greater proportion of patients compared to early stages of oral cancer. These results indicate the need for targeted public health initiatives to improve patient knowledge.

Interpreting and assessing confidence in network meta-analysis results: an introduction for clinicians.

PURPOSE: We aimed to provide clinicians with introductory guidance for interpreting and assessing confidence in on Network meta-analysis (NMA) results. METHODS: We reviewed current literature on NMA and summarized key points. RESULTS: Network meta-analysis (NMA) is a statistical method for comparing the efficacy of three or more interventions simultaneously in a single analysis by synthesizing both direct and indirect evidence across a network of randomized clinical trials. It has become increasingly popular in healthcare, since direct evidence (head-to-head randomized clinical trials) are not always available. NMA methods are categorized as either Bayesian or frequentist, and while the two mostly provide similar results, the two approaches are theoretically different and require different interpretations of the results. CONCLUSIONS: We recommend a careful approach to interpreting NMA results and the validity of an NMA depends on its underlying statistical assumptions and the quality of the evidence used in the NMA.

Mobile Health Interventions and RCTs: Structured Taxonomy and Research Framework.

Mobile Health Interventions (MHIs) have addressed a range of healthcare challenges and have been evaluated using Randomized Controlled Trials (RCTs) to establish clinical effectiveness. Using PRISMA we conducted a systematic literature review of RCTs for MHIs and identified 70 studies which were analyzed and classified using Nickerson-Varshney-Muntermann (NVM) taxonomy. From the resultant iterations of the taxonomy, we extracted insights from the categorized studies. RCTs cover a wide range of health conditions including chronic diseases, general wellness, unhealthy practices, family planning, end-of-life, and post-transplant care. The MHIs that were utilized by the RCTs were varied as well, although most studies did not find significant differences between MHIs and usual care. The challenges for MHI-based RCTs include the use of technologies, delayed outcomes, patient recruitment, patient retention, and complex regulatory requirements. These variances can lead to a higher rate of Type I/Type II errors. Further considerations are the impact of infrastructure, contextual and cultural factors, and reductions in the technological relevancy of the intervention itself. Finally, due to the delayed effect of most outcomes, RCTs of insufficient duration are unable to measure significant, lasting improvements. Using the insights from seventy identified studies, we developed a classification of existing RCTs along with guidelines for MHI-based RCTs and a research framework for future RCTs. The framework offers opportunities for (a) personalization of MHIs, (b) use of richer technologies, and (c) emerging areas for RCTs.

Frailty status among older critically ill patients with severe acute kidney injury.

BACKGROUND: Frailty status among critically ill patients with acute kidney injury (AKI) is not well described despite its importance for prognostication and informed decision-making on life-sustaining therapies. In this study, we aim to describe the epidemiology of frailty in a cohort of older critically ill patients with severe AKI, the outcomes of patients with pre-existing frailty before AKI and the factors associated with a worsening frailty status among survivors. METHODS: This was a secondary analysis of a prospective multicentre observational study that enrolled older (age > 65 years) critically ill patients with AKI. The clinical frailty scale (CFS) score was captured at baseline, at 6 months and at 12 months among survivors. Frailty was defined as a CFS score of ≥ 5. Demographic, clinical and physiological variables associated with frailty as baseline were described. Multivariable Cox proportional hazard models were constructed to describe the association between frailty and 90-day mortality. Demographic and clinical factors associated with worsening frailty status at 6 months and 12 months were described using multivariable logistic regression analysis and multistate models. RESULTS: Among the 462 patients in our cohort, median (IQR) baseline CFS score was 4 (3-5), with 141 (31%) patients considered frail. Pre-existing frailty was associated with greater hazard of 90-day mortality (59% (n = 83) for frail vs. 31% (n = 100) for non-frail; adjusted hazards ratio [HR] 1.49; 95% CI 1.11-2.01, p = 0.008). At 6 months, 68 patients (28% of survivors) were frail. Of these, 57% (n = 39) were not classified as frail at baseline. Between 6 and 12 months of follow-up, 9 (4% of survivors) patients transitioned from a frail to a not frail status while 10 (4% of survivors) patients became frail and 11 (5% of survivors) patients died. In multivariable analysis, age was independently associated with worsening CFS score from baseline to 6 months (adjusted odds ratio [OR] 1.08; 95% CI 1.03-1.13, p = 0.003). CONCLUSIONS: Pre-existing frailty is an independent risk factor for mortality among older critically ill patients with severe AKI. A substantial proportion of survivors experience declining function and worsened frailty status within one year.

Herd immunity alters the conditions for performing dose schedule comparisons: an individual-based model of pneumococcal carriage.

BACKGROUND: There is great interest in the use of reduced dosing schedules for pneumococcal conjugate vaccines, a strategy premised on maintaining an acceptable level of protection against disease and carriage of the organism. We asked about the practicality of measuring differential effectiveness against carriage in a population with and without widespread use of the vaccine for infants. METHODS: We adapted an existing transmission-dynamic, individual-based stochastic model fitted to the prevaccine epidemiology of pneumococcal carriage in the United States, and compared the observed vaccine-type carriage prevalence in different arms of a simulated trial with one, two, or three infant doses plus a 12-month booster. Using these simulations, we calculated vaccine efficacy that would be estimated at different times post-enrollment in the trial and calculated required sample sizes to see a difference in carriage prevalence. RESULTS: In a pneumococcal conjugate vaccine (PCV)-naïve population, the difference in vaccine-type (VT) pneumococcal carriage prevalence between trial arms was less than 7% and varied with sampling time. In a population already receiving routine PCV administration, VT pneumococcal prevalence is nearly indistinguishable between trial arms. Relative efficacy of different dosing schedules was strongly dependent on the time between enrollment and sampling, with maximal prevalence differences reached 1-3 years post-enrollment. Moreover, vaccine efficacy estimates were typically slightly higher in trials in communities already receiving vaccination. Despite this, much larger sample sizes-by more than an order of magnitude-are required for a vaccine trial conducted in a population receiving routine PCV administration as compared to in a PCV-naïve population. CONCLUSIONS: These findings highlight some underappreciated aspects of clinical trials of pneumococcal conjugate vaccines with efficacy endpoints, such as the context- and time-dependence of efficacy estimates. They support the wisdom of conducting comparative dose schedule trials of conjugate vaccine effects on carriage in vaccine-naïve populations.

Health Locus of Control and Medical Behavioral Interventions: Systematic Review and Recommendations.

BACKGROUND: Health locus of control (HLOC) is a theory that describes how individuals perceive different forces that influence their lives. The concept of a locus of control can affect an individual's likelihood to commit to behaviors related to their health. This study explores the literature on the relationships between HLOC and medical behavioral interventions. OBJECTIVE: This study aims to better understand how HLOC constructs can potentially affect patient responses to health behavioral interventions and to propose a series of guidelines for individuals interested in designing medical behavioral interventions related to HLOC. METHODS: We used the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology and performed an analysis of 50 papers related to the topic of HLOC and medical behavioral interventions. Inclusion criteria were studies that had a behavioral intervention involving patients and contained a metric of at least 1 of the constructs related to HLOC. The initial screening and search were conducted by 2 researchers (AY and SM) separately. The results were then combined and compared. RESULTS: Our findings explore the influence of different levels of HLOC along with the importance of both patient- and health-related context when assessing the relationships between HLOC constructs and the likelihood of health behavior change. The findings show that different constructs related to HLOC can act as reliable predictors for patient responses to medical behavioral interventions. Patients who score higher on internal HLOC measures are more likely to exhibit behaviors that are consistent with positive health outcomes. Patients who score higher on chance HLOC are more likely to exhibit behaviors that may lead to adverse health outcomes. These conclusions are supported by most of the 50 studies surveyed. CONCLUSIONS: We propose guidelines for individuals designing medical behavioral interventions so that they can make use of these relationships linked to HLOC. The three guidelines suggested are as follows: (1) in most situations, improving internal HLOC will improve health outcomes for patients; (2) patients with high external HLOC should be further studied to determine the source of the external HLOC; and (3) patients with a high chance HLOC are less likely to follow preventative behaviors or be responsive to interventions. Limitations of the study are that the primary search and analysis were conducted by 2 principal researchers (AY and SM). Interpretation and development of the guidelines are subject to individual interpretation of results and may not be applicable to all contexts.