Is human height based on a Lucas sequence relationship between the foot height, tibial length, femur length and upper body length?

This is a retrospective chart and radiographic review of 145 patients who underwent full-body EOS imaging; 109 males and 36 females. The mean ages of the female and male subsets are 28.8 (SD = 11.6) years and 29.5 (SD = 11.8) years, respectively. The sum of the foot height (Ft) and the tibial length (T) for each subject was compared to their femur length (Fe). Subsequently, the sum of the tibial (T) and femoral lengths (Fe) were compared to their respective upper body lengths (UB), as measured from the tops of the femoral heads. A linear regression test was performed to determine whether a Lucas sequence-based relationship exists between Ft + T and Fe, and between T + Fe and UB. The regression for the relationship between Ft + T and Fe for the entire cohort (R = 0.82, R2 = 0.70), the female subset (R = 0.94, R2 = 0.88) and the male subset (R = 0.75, R2 = 0.57), all demonstrated a strong positive correlation between Ft + T and Fe and showed that Ft + T is a likely predictor of Fe. The regression test for the entire cohort demonstrated a moderately positive correlation between T + Fe and UB (R = 0.41, R2 = 0.17, F(1, 145) = 29.42, p = 2.4E-07). A stronger correlation was found for the relationship between T + Fe and UB (R = 0.57, R2 = 0.32, F(1, 35) = 16.64, p = 2.5E-05) for the female subset relative to the male subset (R = 0.20, R2 = 0.038, F(1, 35) = 4.37, p = 0.04). There appears to be a Lucas sequence relationship between the lengths of the foot height, tibial length, femoral length and upper body length, which together make up standing height. This mathematical proportion relationship is stronger in females than males.

Effect of incisal preparation design on the fracture strength of monolithic zirconia-reinforced lithium silicate laminate veneers.

PURPOSE: This study aimed to assess the fracture resistance of monolithic zirconia-reinforced lithium silicate laminate veneers (LVs) fabricated on various incisal preparation designs. MATERIALS AND METHODS: Sixty maxillary central incisors with various preparation designs were 3D-printed, 15 each, including preparation for: (1) LV with feathered-edge design; (2) LV with butt-joint design; (3) LV with palatal chamfer; and (4) full-coverage crown. Restorations were then designed and manufactured from zirconia-reinforced lithium silicate (ZLS) following the contour of a pre-operation scan. Restorations were bonded to the assigned preparation using resin cement and following the manufacturer's instructions. Specimens were then subjected to 10,000 thermocycles at 5 to 55°C with a dwell time of 30 s. The fracture strength of specimens was then assessed using a universal testing machine at a crosshead speed of 1.0 mm/min. One-way ANOVA and Bonferroni correction multiple comparisons were used to assess the fracture strength differences between the test groups (α = 0.001). Descriptive fractographic analysis of specimens was carried out with scanning electron microscopy images. RESULTS: Complete coverage crown and LV with palatal chamfer design had the highest fracture resistance values (781.4 ± 151.4 and 618.2 ± 112.6 N, respectively). Single crown and LV with palatal chamfer had no significant difference in fracture strength (p > 05). LV with feathered-edge and butt-joint designs provided significantly (p < 05) lower fracture resistance than complete coverage crown and LV with palatal chamfer design. CONCLUSION: The fracture resistance of chairside milled ZLS veneers was significantly influenced by the incisal preparation designs tested. Within the limitation of this study, when excessive occlusal forces are expected, LV with palatal chamfer display is the most conservative method of fabricating an indirect restoration.

Simultaneous Limb Lengthening With Ankle Fusion Using an Internal Lengthening Nail.

We reviewed 18 limbs in 17 patients who underwent ankle fusion with simultaneous tibial lengthening with a magnetic internal lengthening nail. All patients had preoperative limb length discrepancy (LLD) (mean 4.9 cm (2.6-7.6 cm)) with ankle deformity. The ankle was fused from medial or lateral approaches using screws/plate constructs placed adjacent to the retrograde Precise nail. Lengthening was carried out by a distal 1/3 tibial osteotomy. Clinical and radiographic measures were performed after a mean follow-up of 20 months (12-37 months). The mean amount of lengthening performed was 4 cm (1.8-7.2 cm). The final mean LLD was 1 cm (0.7-1.1 cm), which was statistically significant (p<0.01) as compared to preoperative. The foot was plantigrade in all cases. The mean foot rotation was 10° (5-15°) external, relative to the knee. At final follow-up all patients reported minimal to no pain, and all claimed to be walking more functionally than before surgery. Ankle fusion and limb lengthening was achieved in all cases. Combining both treatments by using an internal lengthening nail was very effective and avoided leaving patients with a dysfunctional LLD or of having a separate limb lengthening procedure. This is the first report of such a combined treatment of ankle fusion with internal tibial lengthening nail.

Deformity Reconstruction Surgery for Blount's Disease.

Blount's disease is an idiopathic developmental abnormality affecting the medial proximal tibia physis resulting in a multi-planar deformity with pronounced tibia varus. A single cause is unknown, and it is currently thought to result from a multifactorial combination of hereditary, mechanical, and developmental factors. Relationships with vitamin D deficiency, early walking, and obesity have been documented. Regardless of the etiology, the clinical and radiographic findings are consistent within the two main groups. Early-onset Blount's disease is often bilateral and affects children in the first few years of life. Late-onset Blount's disease is often unilateral and can be sub-categorized as juvenile tibia vara (ages 4-10), and adolescent tibia vara (ages 11 and older). Early-onset Blount's disease progresses to more severe deformities, including depression of the medial tibial plateau. Additional deformities in both groups include proximal tibial procurvatum, internal tibial torsion, and limb length discrepancy. Compensatory deformities in the distal femur and distal tibia may occur. When non-operative treatment fails the deformities progress through skeletal maturity and can result in pain, gait abnormalities, premature medial compartment knee arthritis, and limb length discrepancy. Surgical options depend on the patient's age, weight, extent of physeal involvement, severity, and number of deformities. They include growth modulation procedures such as guided growth for gradual correction with hemi-epiphysiodesis and physeal closure to prevent recurrence and equalize limb lengths, physeal bar resection, physeal distraction, osteotomies with acute correction and stabilization, gradual correction with multi-planar dynamic external fixation, and various combinations of all modalities. The goals of surgery are to restore normal joint and limb alignment, equalize limb lengths at skeletal maturity, and prevent recurrence. The purpose of this literature review is to delineate basic concepts and reconstructive surgical treatment strategies for patients with Blount's disease.

Informing Patient-Centered Care Through Stakeholder Engagement and Highly Stratified Quantitative Benefit-Harm Assessments.

OBJECTIVES: In a previous project aimed at informing patient-centered care for people with multiple chronic conditions, we performed highly stratified quantitative benefit-harm assessments for 2 top priority questions. In this current work, our goal was to describe the process and approaches we developed and to qualitatively glean important elements from it that address patient-centered care. METHODS: We engaged patients, caregivers, clinicians, and guideline developers as stakeholder representatives throughout the process of the quantitative benefit-harm assessment and investigated whether the benefit-harm balance differed based on patient preferences and characteristics (stratification). We refined strategies to select the most applicable, valid, and precise evidence. RESULTS: Two processes were important when assessing the balance of benefits and harms of interventions: (1) engaging stakeholders and (2) stratification by patient preferences and characteristics. Engaging patients and caregivers through focus groups, preference surveys, and as co-investigators provided value in prioritizing research questions, identifying relevant clinical outcomes, and clarifying the relative importance of these outcomes. Our strategies to select evidence for stratified benefit-harm assessments considered consistency across outcomes and subgroups. By quantitatively estimating the range in the benefit-harm balance resulting from true variation in preferences, we clarified whether the benefit-harm balance is preference sensitive. CONCLUSIONS: Our approaches for engaging patients and caregivers at all phases of the stratified quantitative benefit-harm assessments were feasible and revealed how sensitive the benefit-harm balance is to patient characteristics and individual preferences. Accordingly, this sensitivity can suggest to guideline developers when to tailor recommendations for specific patient subgroups or when to explicitly leave decision making to individual patients and their providers.

Outcome preferences of older people with multiple chronic conditions and hypertension: a cross-sectional survey using best-worst scaling.

BACKGROUND: Older people with hypertension and multiple chronic conditions (MCC) receive complex treatments and face challenging trade-offs. Patients' preferences for different health outcomes can impact multiple treatment decisions. Since evidence about outcome preferences is especially scarce among people with MCC our aim was to elicit preferences of people with MCC for outcomes related to hypertension, and to determine how these outcomes should be weighed when benefits and harms are assessed for patient-centered clinical practice guidelines and health economic assessments. METHODS: We sent a best-worst scaling preference survey to a random sample identified from a primary care network of Kaiser Permanente (Colorado, USA). The sample included individuals age 60 or greater with hypertension and at least two other chronic conditions. We assessed average ranking of patient-important outcomes using conditional logit regression (stroke, heart attack, heart failure, dialysis, cognitive impairment, chronic kidney disease, acute kidney injury, fainting, injurious falls, low blood pressure with dizziness, treatment burden) and studied variation across individuals. RESULTS: Of 450 invited participants, 217 (48%) completed the survey, and we excluded 10 respondents who had more than two missing choices, resulting in a final sample of 207 respondents. Participants ranked stroke as the most worrisome outcome and treatment burden as the least worrisome outcome (conditional logit parameters: 3.19 (standard error 0.09) for stroke, 0 for treatment burden). None of the outcomes were always chosen as the most or least worrisome by more than 25% of respondents, indicating that all outcomes were somewhat worrisome to respondents. Predefined subgroup analyses according to age, self-reported life-expectancy, degree of comorbidity, number of medications and antihypertensive treatment did not reveal meaningful differences. CONCLUSIONS: Although some outcomes were more worrisome to patients than others, our results indicate that none of the outcomes should be disregarded for clinical practice guidelines and health economic assessments.

Balance of benefits and harms of different blood pressure targets in people with multiple chronic conditions: a quantitative benefit-harm assessment.

OBJECTIVE: Recent studies suggest that a systolic blood pressure (SBP) target of 120 mm Hg is appropriate for people with hypertension, but this is debated particularly in people with multiple chronic conditions (MCC). We aimed to quantitatively determine whether benefits of a lower SBP target justify increased risks of harm in people with MCC, considering patient-valued outcomes and their relative importance. DESIGN: Highly stratified quantitative benefit-harm assessment based on various input data identified as the most valid and applicable from a systematic review of evidence and based on weights from a patient preference survey. SETTING: Outpatient care. PARTICIPANTS: Hypertensive patients, grouped by age, gender, prior history of stroke, chronic heart failure, chronic kidney disease and type 2 diabetes mellitus. INTERVENTIONS: SBP target of 120 versus 140 mm Hg for patients without history of stroke. PRIMARY AND SECONDARY OUTCOME MEASURES: Probability that the benefits of a SBP target of 120 mm Hg outweigh the harms compared with 140 mm Hg over 5 years (primary) with thresholds >0.6 (120 mm Hg better), <0.4 (140 mm Hg better) and 0.4 to 0.6 (unclear), number of prevented clinical events (secondary), calculated with the Gail/National Cancer Institute approach. RESULTS: Considering individual patient preferences had a substantial impact on the benefit-harm balance. With average preferences, 120 mm Hg was the better target compared with 140 mm Hg for many subgroups of patients without prior stroke, especially in patients over 75. For women below 65 with chronic kidney disease and without diabetes and prior stroke, 140 mm Hg was better. The analyses did not include mild adverse effects, and apply only to patients who tolerate antihypertensive treatment. CONCLUSIONS: For most patients, a lower SBP target was beneficial, but this depended also on individual preferences, implying individual decision-making is important. Our modelling allows for individualised treatment targets based on patient preferences, age, gender and co-morbidities.

A benefit-harm analysis of adding basal insulin vs. sulfonylurea to metformin to manage type II diabetes mellitus in people with multiple chronic conditions.

OBJECTIVES: The benefits and harms of diabetes treatments need to be carefully weighed in people with type II diabetes mellitus (DM) and multiple chronic conditions (MCCs). Our objective was to quantitatively assess the benefits and harms of the addition of basal insulin (insulin) vs. sulfonylurea (SU) to metformin in people with DM and MCCs. STUDY DESIGN AND SETTING: Data inputs into the benefit-harms analysis included (1) baseline risks of patient-centered outcomes (death, myocardial infarction, stroke, severe hypoglycemia, diarrhea, nausea) from cohorts and trials; (2) treatment effects for the addition of insulin vs. SU from a network meta-analysis; and (3) patient preference survey for outcome weights. Statistical analysis calculated the probability that adding insulin has greater benefits than harms, when compared with an SU, overall and by prespecified subgroups. RESULTS: Including the six outcomes, the probability of net benefit for insulin compared with SU was similar, across subgroups by age and diabetes duration (probability range, using conditional logit weights: 0.44-0.56). Adding patient preferences for treatment burden associated with insulin injections shifted the probability to favor SU over insulin (probability range, using conditional logit weights: 0.01-0.12). CONCLUSION: In people with DM and MCCs, we demonstrated incomplete evidence to conclude if basal insulin or SU should be added in people with DM and MCCs on metformin alone. The benefit-harm balance was sensitive to treatment preferences, that is., perceived treatment burden, indicating the importance of shared-decision making in caring for people with MCCs who are at high risk for experiencing harms associated with diabetes management.

Developing and Testing the Agency for Healthcare Research and Quality's National Guideline Clearinghouse Extent of Adherence to Trustworthy Standards (NEATS) Instrument.

In 2011, the Institute of Medicine (IOM) (now the National Academy of Medicine) published standards for trustworthy guidelines and recommended that the National Guideline Clearinghouse (NGC) of the Agency for Healthcare Research and Quality clearly indicate the extent to which guidelines adhere to these standards. To accomplish this, the authors developed and tested the NGC Extent of Adherence to Trustworthy Standards (NEATS) instrument. The standards were operationalized as an instrument containing 15 items that cover disclosure of the funding source; disclosure and management of conflicts of interest; multidisciplinary input; incorporation of patient perspectives; rigorous systematic review; recommendations accompanied by rationale, assessment of benefits and harms, clear linkage to the evidence, and assessment of strength of evidence and strength of recommendation; clear articulation of recommendations; external review by diverse stakeholders; and plans for updating. After multiple rounds of feedback from experts on clinical practice guideline development, the external validity and interrater reliability of the instrument were evaluated. For each item, 80% to 100% of survey respondents judged it to be a good measure of the IOM standards. All external stakeholders stated that NEATS was suitable for its intended goal. Interrater reliability for the final NEATS instrument had a weighted κ of 0.73. The NEATS instrument is a focused tool that provides a concise evaluation of a guideline's adherence to the IOM standards for trustworthy guidelines. It has good external validity among guideline developers and good interrater reliability across trained reviewers.

Iliac crest apophysis transfer to treat stump overgrowth after limb amputation in children: case series and literature review.

PURPOSE: Stump overgrowth is the main problem of limb amputation in children. Many surgical procedures have been developed to overcome the problem, but all have shown inconsistent results. The only surgical procedure that has been successful in preventing overgrowth is capping of the amputated limb with a cartilaginous cap taken from the amputated limb, usually from the head of fibula. A donor site is not available in revision cases. Iliac crest apophysis transfer was suggested to treat the condition, but has never been previously reported. The purpose of this study is to review the results of iliac crest apophysis transfer to prevent stump overgrowth. METHOD: Five children with amputation stump overgrowth underwent iliac apophyseal transfer to cap the resection site of the overgrowth. RESULTS: Retrospective review showed that three of the five suffered recurrent stump overgrowth two to four years after the index surgery. All three were revised again. One patient was lost to follow-up. CONCLUSION: Although many studies showed capping of the stump with cartilaginous cap to be successful in preventing stump overgrowth, iliac crest apophysis transfer was only successful in one of four cases available to follow-up (25%). This is not a reliable enough method to be used routinely.

Engaging Stakeholders to Inform Clinical Practice Guidelines That Address Multiple Chronic Conditions.

BACKGROUND: Having more than one chronic condition is common and is associated with greater health care utilization, higher medication burden and complexity of treatment. However, clinical practice guidelines (CPGs) do not routinely address the balance between harms and benefits of treatments for people with multiple chronic conditions (MCCs). OBJECTIVE: To partner with the Kaiser Permanente Integrated Cardiovascular Health (ICVH) program to engage multiple stakeholders in a mixed-methods approach in order to: 1) identify two high-priority clinical questions related to MCCs, and 2) understand patients' and family caregivers' perceptions of meaningful outcomes to inform benefit/harm assessments for these two high-priority questions. These clinical questions and outcomes will be used to inform CPG recommendations for people with MCCs. DESIGN AND PARTICIPANTS: The ICVH program provided 130 topics rank-ordered by the potential for finding evidence that would change clinical recommendations regarding the topic. We used a modified Delphi method to identify and reword topics into questions relevant to people with MCCs. We used two sets of focus groups (n = 27) to elicit patient and caregiver perspectives on two important research questions and relevant patient-important outcomes on benefit/harm balance for people with MCCs. KEY RESULTS: Co-investigators, patients and caregivers identified "optimal blood pressure goals" and "diabetes medication management" as important clinical topics for CPGs related to people with MCCs. Stakeholders identified a list of relevant outcomes to be addressed in future CPG development including 1) physical function and energy, 2) emotional health and well-being, 3) avoidance of treatment burden, side effects and risks, 4) interaction with providers and health care system, and 5) prevention of adverse long-term health outcomes. CONCLUSIONS: Through the application of a mixed-methods process, we identified the questions regarding optimal blood pressure goals and diabetes medication management, along with related patient-centered outcomes, to inform novel evidence syntheses for those with MCCs. This study provides the lessons learned and a generalizable process for CPG developers to engage patient and caregivers in priority-setting for the translation of evidence into future CPGs. Ultimately, engaging patient and stakeholders around MCCs could improve the relevance of CPGs for the care of people with MCCs.

Guidelines International Network: Principles for Disclosure of Interests and Management of Conflicts in Guidelines.

Conflicts of interest (COIs) have been defined by the American Thoracic Society as "a divergence between an individual's private interests and his or her professional obligations such that an independent observer might reasonably question whether the individual's professional actions or decisions are motivated by personal gain, such as direct financial, academic advancement, clinical revenue streams, or community standing." In the context of guideline development, the concerns are not simply about identifying and disclosing direct financial or indirect COIs. Despite this recognition, the management of COIs in guidelines is often unsatisfactory. In response to requests from its international membership and informed by existing syntheses of the evidence and policies of international organizations, the Guidelines International Network Board of Trustees developed guidance on the disclosure of interests and management of COIs. Current approaches are relatively similar throughout the guideline development community, with an increasing recognition of the importance of disclosing and managing indirect COIs. Although there are differences in detail among the approaches, the similarities allow for the formulation of 9 core principles for managing COIs. In formulating these principles, the Guidelines International Network Board of Trustees recognizes that COIs cannot be totally avoided when panel members are being chosen for certain guidelines or in certain settings; thus, the important issue is the management of COIs in a fair, judicious, transparent manner.

Transparency matters: Kaiser Permanente's National Guideline Program methodological processes.

INTRODUCTION: The practice-guideline process of collecting, critically appraising, and synthesizing available evidence, then developing expert panel recommendations based on appraised evidence, makes it possible to provide high-quality care for patients. Unwanted variability in the quality and rigor of evidence summaries and Clinical Practice Guidelines has been a long-standing challenge for clinicians seeking evidence-based guidance to support patient care decisions. METHODS: A multidisciplinary group of stakeholders, with representation from all eight Kaiser Permanente Regions, is responsible for creating National Guidelines. Conducting high-quality systematic reviews and creating clinical guidelines are time-, labor-, and resource-intensive processes, which raises challenges for an organization striving to balance rigor with efficiency. For these reasons, the National Guideline Program elected to allow for the identification, assessment, and possible adoption of existing evidence-based guidelines and systematic reviews using the ADAPTE; Appraisal of Guidelines Research and Evaluation; Assessment of Multiple Systematic Reviews (AMSTAR); and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) frameworks. If no acceptable external guidelines are identified, the Guideline Development Team then systematically searches for relevant high-quality systematic reviews, meta-analyses, and original studies. Existing systematic reviews are assessed for quality using a measurement tool to assess systematic reviews (the AMSTAR systematic review checklist). STUDY APPRAISAL: Following the screening and selection process, the included studies (the "body of evidence") are critically appraised for quality, using the GRADE methodology, which focuses on four key factors that must be considered when assigning strength to a recommendation: balance between desirable and undesirable effects, quality of evidence, values and preferences, and cost. The evidence is then used to create preliminary clinical recommendations. The strength of these recommendations is graded to reflect the extent to which a guideline panel is confident that the desirable effects of an intervention outweigh undesirable effects (or vice versa) across the range of patients for whom the recommendation is intended. DISSEMINATION: The Care Management Institute disseminates all KP national guidelines to its eight Regions via postings on its Clinical Library Intranet site, a Web-based internal information resource.

The morningside initiative: collaborative development of a knowledge repository to accelerate adoption of clinical decision support.

The Morningside Initiative is a public-private activity that has evolved from an August, 2007, meeting at the Morningside Inn, in Frederick, MD, sponsored by the Telemedicine and Advanced Technology Research Center (TATRC) of the US Army Medical Research Materiel Command. Participants were subject matter experts in clinical decision support (CDS) and included representatives from the Department of Defense, Veterans Health Administration, Kaiser Permanente, Partners Healthcare System, Henry Ford Health System, Arizona State University, and the American Medical Informatics Association (AMIA). The Morningside Initiative was convened in response to the AMIA Roadmap for National Action on Clinical Decision Support and on the basis of other considerations and experiences of the participants. Its formation was the unanimous recommendation of participants at the 2007 meeting which called for creating a shared repository of executable knowledge for diverse health care organizations and practices, as well as health care system vendors. The rationale is based on the recognition that sharing of clinical knowledge needed for CDS across organizations is currently virtually non-existent, and that, given the considerable investment needed for creating, maintaining and updating authoritative knowledge, which only larger organizations have been able to undertake, this is an impediment to widespread adoption and use of CDS. The Morningside Initiative intends to develop and refine (1) an organizational framework, (2) a technical approach, and (3) CDS content acquisition and management processes for sharing CDS knowledge content, tools, and experience that will scale with growing numbers of participants and can be expanded in scope of content and capabilities. Intermountain Healthcare joined the initial set of participants shortly after its formation. The efforts of the Morningside Initiative are intended to serve as the basis for a series of next steps in a national agenda for CDS. It is based on the belief that sharing of knowledge can be highly effective as is the case in other competitive domains such as genomics. Participants in the Morningside Initiative believe that a coordinated effort between the private and public sectors is needed to accomplish this goal and that a small number of highly visible and respected health care organizations in the public and private sector can lead by example. Ultimately, a future collaborative knowledge sharing organization must have a sustainable long-term business model for financial support.

Hepatectomy enables prolonged survival in select patients with isolated noncolorectal liver metastasis.

OBJECTIVE: This study was done to determine the benefit of undergoing liver resection for noncolorectal metastasis. METHODS: A single-institution retrospective review of all patients (n = 95) who underwent hepatic resection for a noncolorectal liver metastasis from 1990 to 2005 was performed. Primary outcomes measure was months of patient survival after liver resection. RESULTS: Median patient age was 58 years (range 19 to 83 years). There were 37 men (38.9%) and 58 women (61.1%). The 30-day postoperative mortality rate was 2.1%, and postoperative complications developed in 15.8% of patients. Mean hospital stay was 7 days (range 4 to 25 days). Median time of survival from date of liver resection was 36 months, and 5-year survival rate was 34.9%. Primary tumor sites were identified as foregut or gastrointestinal in 16.8% and nongastrointestinal in 83.2%. Patients with a nonforegut primary tumor had a median survival time twice as long as those with foregut primaries (49 months versus 20 months, p < 0.001). Multiple liver metastases were an independent prognostic factor for worse outcomes with a hazard ratio of 3.3 (p = 0.007). No treatment-dependent variables (initial treatment modality, extent of liver resection, margins, complications) were found on multivariable analysis to be important prognostic factors. CONCLUSIONS: In select patients with any of a variety of malignancies metastatic to the liver, prolonged survival can result from liver resection, especially in those with a single, resectable tumor from a nongastrointestinal primary site.

Does this patient have Parkinson disease?

CONTEXT: Diagnosis of Parkinson disease (PD) remains challenging. An accurate diagnosis is important because effective symptomatic treatment for PD is available. OBJECTIVE: To systematically review the literature for information on the precision and accuracy of the clinical examination for diagnosing PD. DATA SOURCES: MEDLINE database was searched for all English-language articles related to the diagnosis of PD published from January 1966 through April 2001. The reference lists of all articles retrieved were searched for additional relevant sources. STUDY SELECTION: Studies in which patients presented with 1 or more typical features of PD were included if the final diagnosis was confirmed by a suitable criterion standard and data could be extracted to determine the accuracy of 1 or more symptoms or signs. Variability in descriptions of symptoms and signs made it impossible to combine data across existing studies for most findings. DATA SYNTHESIS: We identified 6 studies that met our criteria. The positive (presence) likelihood ratios (LRs) for tremor as a symptom of PD ranged from 1.3 to 17 (range of negative [absence] LRs, 0.24 to 0.60). Tremor as a sign of PD produced a range of positive LRs from 1.3 to 1.5 (negative LRs, 0.47 to 0.61). Clinical features useful in the diagnosis of PD include a history of the combination of symptoms of rigidity and bradykinesia (positive LR, 4.5; negative LR, 0.12); a history of loss of balance (range of positive LRs, 1.6 to 6.6; range of negative LRs, 0.29 to 0.35), symptoms of micrographia (range of positive LRs, 2.8 to 5.9; range of negative LRs, 0.30 to 0.44), and a history of shuffling gait (range of positive LRs, 3.3 to 15; range of negative LRs, 0.32 to 0.50). Trouble with certain tasks such as turning in bed (positive LR, 13; negative LR, 0.56), opening jars (positive LR, 6.1; negative LR, 0.26), and rising from a chair (range of positive LRs, 1.9 to 5.2; range of negative LRs, 0.39 to 0.58). Useful signs include the glabella tap test (positive LR, 4.5; negative LR, 0.13), difficulty walking heel-to-toe (positive LR, 2.9; negative LR, 0.32), and rigidity (range of positive LRs, 0.53 to 2.8; range of negative LRs, 0.38 to 1.6). Significant selection bias was detected in all studies included for review. CONCLUSIONS: Symptoms of tremor, rigidity, bradykinesia, micrographia, shuffling gait, and difficulty with the tasks of turning in bed, opening jars, and rising from a chair should be carefully reviewed in all patients with suspected PD. The glabella tap and heel-to-toe tests also should be assessed.