Part II: Blood Transfusion and Donor Exposure in the Surgical Management of Trigonocephaly Patients: A Protocol From Alder Hey Craniofacial Unit.

Trigonocephaly is a craniofacial malformation caused by premature fusion of the metopic suture. Surgical correction frequently results in the need for blood transfusion. Transfusion complications include transfusion-transmitted infections (TTIs), immune-mediated reactions, and volume overload. Donor exposure (DE) describes the number of blood products from unique donors with increasing DE equating to an increased risk of TTI. We evaluate data on 204 trigonocephaly patients covering 20 years of practice with respect to blood transfusions and DE. This represents the largest series from a single unit to date. A protocol based on our experiences has been devised that summarizes the key interventions we recommend to minimize blood transfusions and DE in craniofacial surgery. Patients operated on between 2000 and 2020 were included. DE and a range of values were calculated including estimated red cell loss (ERCL) and estimated red cell volume transfused (ERCVT). Groups were established by relevant interventions and compared using the Mann-Whitney U test. Mean DE fell from 1.46 at baseline to 0.85 ( P <0.05). Median allogenic transfusion volume fell from 350 mL at baseline to 250 mL ( P <0.05). Median ERCL fell from 15.05 mL/kg at baseline to 12.39 mL/kg and median ERCVT fell from 20.85 to 15.98 mL/kg. Changes in ERCL and ERCVT did not reach statistical significance. DE can be minimized with the introduction of key interventions such as a restrictive transfusion policy, preoperative iron, cell saver, tranexamic acid, and use of a matchstick burr for osteotomies.

The Paediatric Vault Score (PVS)-A Novel Scoring Tool for Prioritisation of Surgical Management of Craniosynostosis Patients.

Craniosynostosis is the premature fusion of the skull sutures, resulting in abnormal skull shape and volume. Timely management is a priority in avoiding raised intracranial pressure which can result in blindness and neurodevelopmental delay. Due to the COVID-19 pandemic, theater access was reduced. A risk stratification scoring system was thus devised to score patients attending surgery and aid in prioritization according to surgical need. The authors present the Paediatric Vault Score (PVS), which can also be customized to each unit's individual protocols. Ten patients on the waiting list were randomly selected and their clinical information was summarized in uniform anonymized reports. Six craniofacial consultants were selected as assessors and given 1 week to independently rank the patients from 1 to 10. Each scorer's ranking was verified against the PVS template and concordance was analyzed using the Kendall tau correlation coefficient (KT). Three cycles of the scoring process were carried out. Improvements were made to the scoring tool following cycle 1. Cycle 1 revealed 2 clinicians to be concordant with the PVS system and 4 to be discordant. Cycle 2 revealed all 6 clinicians to be concordant, with a mean KT score of 0.61. The final cycle revealed all 6 clinicians to be concordant, with a mean KT score of 0.70. Four scorers increased their concordance once the scoring sheet was introduced. Kendall's correlation of concordance calculated the interrater reliability to be 0.81. The PVS is the first known vault scoring system to aid in risk stratification and waiting list prioritization.

Adverse drug reactions, multimorbidity and polypharmacy: a prospective analysis of 1 month of medical admissions.

OBJECTIVE: To ascertain the burden and associated cost of adverse drug reactions (ADRs), polypharmacy and multimorbidity through a prospective analysis of all medical admissions to a large university teaching hospital over a 1-month period. DESIGN: Prospective observational study. SETTING: Liverpool University Hospital Foundation National Health Service (NHS) Trust, England. PARTICIPANTS: All medical admissions with greater than 24-hour stay over a 1-month period. MAIN OUTCOME MEASURES: Prevalence of admissions due to an ADR and associated mortality, prevalence and association of multimorbidity and polypharmacy with ADRs, and estimated local financial cost of admissions where an ADR was a contributing or main reason for admission with projected costs for NHS in England. RESULTS: There were 218 identified patient admissions with an ADR giving a prevalence of 18.4%. The majority of these (90.4%) were ADRs that directly resulted in or contributed to admission. ADRs thus accounted for 16.5% of total admissions. Those with an ADR were on average taking more medicines (10.5 vs 7.8, p<0.01) and had more comorbidities than those without an ADR (6.1 vs 5.2, p<0.01). Drugs most commonly implicated were diuretics, steroid inhalers, anticoagulants and antiplatelets, proton pump inhibitors, chemotherapeutic agents and antihypertensives. 40.4% of ADRs were classified avoidable or possibly avoidable. The mortality rate due to an ADR was 0.34%. The average length of stay for those with an ADR was 6 days. Direct 1-month cost to the Trust from ADR admissions was £490 716. Extrapolated nationally, the projected annual cost to the NHS in England is 2.21 billion. CONCLUSION: The local prevalence of admission and mortality from ADRs is higher than previously reported. Important factors that could be contributing to this include polypharmacy and multimorbidity. ADRs place a significant burden on patients and healthcare services with associated financial implications. Reducing inappropriate polypharmacy should be a major aim for preventing ADRs.

Surgical microdiscectomy versus transforaminal epidural steroid injection in patients with sciatica secondary to herniated lumbar disc (NERVES): a phase 3, multicentre, open-label, randomised controlled trial and economic evaluation.

BACKGROUND: The optimal invasive treatment for sciatica secondary to herniated lumbar disc remains controversial, with a paucity of evidence for use of non-surgical treatments such as transforaminal epidural steroid injection (TFESI) over surgical microdiscectomy. We aimed to investigate the clinical and cost-effectiveness of these options for management of radicular pain secondary to herniated lumbar disc. METHODS: We did a pragmatic, multicentre, phase 3, open-label, randomised controlled trial at 11 spinal units across the UK. Eligible patients were aged 16-65 years, had MRI-confirmed non-emergency sciatica secondary to herniated lumbar disc with symptom duration between 6 weeks and 12 months, and had leg pain that was not responsive to non-invasive management. Participants were randomly assigned (1:1) to receive either TFESI or surgical microdiscectomy by an online randomisation system that was stratified by centre with random permuted blocks. The primary outcome was Oswestry Disability Questionnaire (ODQ) score at 18 weeks. All randomly assigned participants who completed a valid ODQ at baseline and at 18 weeks were included in the analysis. Safety analysis included all treated participants. Cost-effectiveness was estimated from the EuroQol-5D-5L, Hospital Episode Statistics, medication usage, and self-reported resource-use data. This trial was registered with ISRCTN, number ISRCTN04820368, and EudraCT, number 2014-002751-25. FINDINGS: Between March 6, 2015, and Dec 21, 2017, 163 (15%) of 1055 screened patients were enrolled, with 80 participants (49%) randomly assigned to the TFESI group and 83 participants (51%) to the surgery group. At week 18, ODQ scores were 30·02 (SD 24·38) for 63 assessed patients in the TFESI group and 22·30 (19·83) for 61 assessed patients in the surgery group. Mean improvement was 24·52 points (18·89) for the TFESI group and 26·74 points (21·35) for the surgery group, with an estimated treatment difference of -4·25 (95% CI -11·09 to 2·59; p=0·22). There were four serious adverse events in four participants associated with surgery, and none with TFESI. Compared with TFESI, surgery had an incremental cost-effectiveness ratio of £38 737 per quality-adjusted life-year gained, and a 0·17 probability of being cost-effective at a willingness-to-pay threshold of £20 000 per quality-adjusted life-year. INTERPRETATION: For patients with sciatica secondary to herniated lumbar disc, with symptom duration of up to 12 months, TFESI should be considered as a first invasive treatment option. Surgery is unlikely to be a cost-effective alternative to TFESI. FUNDING: Health Technology Assessment programme of the National Institute for Health Research (NIHR), UK.

Microdiscectomy compared with transforaminal epidural steroid injection for persistent radicular pain caused by prolapsed intervertebral disc: the NERVES RCT.

BACKGROUND: Sciatica is a common condition reported to affect > 3% of the UK population at any time and is most often caused by a prolapsed intervertebral disc. Currently, there is no uniformly adopted treatment strategy. Invasive treatments, such as surgery (i.e. microdiscectomy) and transforaminal epidural steroid injection, are often reserved for failed conservative treatment. OBJECTIVE: To compare the clinical effectiveness and cost-effectiveness of microdiscectomy with transforaminal epidural steroid injection for the management of radicular pain secondary to lumbar prolapsed intervertebral disc for non-emergency presentation of sciatica of < 12 months' duration. INTERVENTIONS: Patients were randomised to either (1) microdiscectomy or (2) transforaminal epidural steroid injection. DESIGN: A pragmatic, multicentre, randomised prospective trial comparing microdiscectomy with transforaminal epidural steroid injection for sciatica due to prolapsed intervertebral disc with < 1 year symptom duration. SETTING: NHS services providing secondary spinal surgical care within the UK. PARTICIPANTS: A total of 163 participants (aged 16-65 years) were recruited from 11 UK NHS outpatient clinics. MAIN OUTCOME MEASURES: The primary outcome was participant-completed Oswestry Disability Questionnaire score at 18 weeks post randomisation. Secondary outcomes were visual analogue scores for leg pain and back pain; modified Roland-Morris score (for sciatica), Core Outcome Measures Index score and participant satisfaction at 12-weekly intervals. Cost-effectiveness and quality of life were assessed using the EuroQol-5 Dimensions, five-level version; Hospital Episode Statistics data; medication usage; and self-reported cost data at 12-weekly intervals. Adverse event data were collected. The economic outcome was incremental cost per quality-adjusted life-year gained from the perspective of the NHS in England. RESULTS: Eighty-three participants were allocated to transforaminal epidural steroid injection and 80 participants were allocated to microdiscectomy, using an online randomisation system. At week 18, Oswestry Disability Questionnaire scores had decreased, relative to baseline, by 26.7 points in the microdiscectomy group and by 24.5 points in the transforaminal epidural steroid injection. The difference between the treatments was not statistically significant (estimated treatment effect -4.25 points, 95% confidence interval -11.09 to 2.59 points). Nor were there significant differences between treatments in any of the secondary outcomes: Oswestry Disability Questionnaire scores, visual analogue scores for leg pain and back pain, modified Roland-Morris score and Core Outcome Measures Index score up to 54 weeks. There were four (3.8%) serious adverse events in the microdiscectomy group, including one nerve palsy (foot drop), and none in the transforaminal epidural steroid injection group. Compared with transforaminal epidural steroid injection, microdiscectomy had an incremental cost-effectiveness ratio of £38,737 per quality-adjusted life-year gained and a probability of 0.17 of being cost-effective at a willingness to pay threshold of £20,000 per quality-adjusted life-year. LIMITATIONS: Primary outcome data was invalid or incomplete for 24% of participants. Sensitivity analyses demonstrated robustness to assumptions made regarding missing data. Eighteen per cent of participants in the transforaminal epidural steroid injection group subsequently received microdiscectomy prior to their primary outcome assessment. CONCLUSIONS: To the best of our knowledge, the NErve Root Block VErsus Surgery trial is the first trial to evaluate the comparative clinical effectiveness and cost-effectiveness of microdiscectomy and transforaminal epidural steroid injection. No statistically significant difference was found between the two treatments for the primary outcome. It is unlikely that microdiscectomy is cost-effective compared with transforaminal epidural steroid injection at a threshold of £20,000 per quality-adjusted life-year for sciatica secondary to prolapsed intervertebral disc. FUTURE WORK: These results will lead to further studies in the streamlining and earlier management of discogenic sciatica. TRIAL REGISTRATION: Current Controlled Trials ISRCTN04820368 and EudraCT 2014-002751-25. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 24. See the NIHR Journals Library website for further project information.

WHAT IS THE PROBLEM?: Sciatica or pain related to nerve irritation travelling down the leg is common in young working adults and most likely to be caused by a 'slipped' (prolapsed) disc. Although the majority of cases get better on their own and within 4­6 weeks, a significant group of patients struggle with disabling symptoms sometimes beyond 1 year. Consequently, patients struggle to maintain their home and working lives. Many treatments are available for sciatica, but simpler treatments (e.g. pain tablets, physiotherapy and changing one's lifestyle) are often not very effective and patients have often tried all of them by the time they are seen in hospital to have tests, such as scans, done. Surgery to remove part of the disc is recommended in cases where the pain is accompanied by severe weakness in one or both legs, or where doctors think that nerves may be damaged because patients have bladder, bowel and sexual functioning difficulties (i.e. red flag symptoms). Surgery works well in alleviation of referred leg pain and also to relieve pressure on a physically compressed nerve that may be showing clinical sign of injury/weakness. An alternative to surgery is to inject a mixture of anaesthetic and steroid close to the site of the disc injury and nerve, but at the moment we do not know whether or not these injections work in the long term. They are cheaper and less invasive, with fewer risks than surgery, such as from anaesthetic or infection. WHAT DID OUR STUDY INVESTIGATE?: This study compared the usefulness of surgery with injections for patients who have had sciatica for < 1 year and who have tried simple remedies but are still in pain. Patients were allocated to have either surgery or the injection. Symptoms (e.g. pain) were assessed after 18 weeks. WHAT DID WE FIND?: We found that there was no significant difference between surgery and injection at the primary end point. Surgery was not significantly different from injection in terms of clinical outcome and was not cost-effective compared with injection. OUR CONCLUSION AND RECOMMENDATION: Given the cost of surgery and the risks to patients, we suggest that further studies should be carried out to explore whether or not all patients with sciatica due to a slipped disc should be considered suitable for an injection, unless there is a good reason not to.

Managing clustering effects and learning effects in the design and analysis of multicentre randomised trials: a survey to establish current practice.

BACKGROUND: Patient outcomes can depend on the treating centre, or health professional, delivering the intervention. A health professional's skill in delivery improves with experience, meaning that outcomes may be associated with learning. Considering differences in intervention delivery at trial design will ensure that any appropriate adjustments can be made during analysis. This work aimed to establish practice for the allowance of clustering and learning effects in the design and analysis of randomised multicentre trials. METHODS: A survey that drew upon quotes from existing guidelines, references to relevant publications and example trial scenarios was delivered. Registered UK Clinical Research Collaboration Registered Clinical Trials Units were invited to participate. RESULTS: Forty-four Units participated (N = 50). Clustering was managed through design by stratification, more commonly by centre than by treatment provider. Managing learning by design through defining a minimum expertise level for treatment provider was common (89%). One-third reported experience in expertise-based designs. The majority of Units had adjusted for clustering during analysis, although approaches varied. Analysis of learning was rarely performed for the main analysis (n = 1), although it was explored by other means. The insight behind the approaches used within and reasons for, or against, alternative approaches were provided. CONCLUSIONS: Widespread awareness of challenges in designing and analysing multicentre trials is identified. Approaches used, and opinions on these, vary both across and within Units, indicating that approaches are dependent on the type of trial. Agreeing principles to guide trial design and analysis across a range of realistic clinical scenarios should be considered.

Funders improved the management of learning and clustering effects through design and analysis of randomized trials involving surgery.

OBJECTIVE: The objective of this study was to provide insight into current practice in planning for, and acknowledging, the presence of learning and clustering effects, by treating center and surgeon, when developing randomized surgical trials. STUDY DESIGN AND SETTING: Complexities associated with delivering surgical interventions, such as clustering effects, by center or surgeon, and surgical learning should be considered at trial design. Main trial publications, within the wider literature, under-report these considerations. Funded applications, within a 4-year period, from a leading UK funding body were searched. Data were extracted on considerations for learning and clustering effects and the driver, funder, or applicant, behind these. RESULTS: Fifty trials were eligible. Managing learning through establishing predefined center and surgeon credentials was common. One planned exploratory analysis of learning within center, and two within surgeon. Clustering, by site and surgeon, was often managed through stratifying randomization, with 81% and 60%, respectively, also planning to subsequently adjust analysis. One-third of responses to referees contained funder led changes accounting for learning and/or clustering. CONCLUSION: This review indicates that researchers do consider impact of learning and clustering, by center and surgeon, during trial development. Furthermore, the funder is identified as a potential driver of considerations.

Randomized trials involving surgery did not routinely report considerations of learning and clustering effects.

OBJECTIVES: To establish current practice of the management of learning and clustering effects, by treating center and surgeon, in the design and analysis of randomized surgical trials. STUDY DESIGN AND SETTING: The need for more surgical randomized trials is well recognized, and in recent years conduct has grown. Rigorous design, conduct, and analyses of such studies is important. Two methodological challenges are clustering effects, by center or surgeon, and surgical learning on trial outcomes. Sixteen leading journals were searched for randomized trials published within a two-year period. Data were extracted on considerations for learning and clustering effects. RESULTS: A total of 247 eligible studies were identified. Trials accounted for learning with 2% using an expertise-based design and 39% accounting for expertise by predefining surgeon credentials. One study analyzed learning. Clustering, by site and surgeon, was commonly managed by stratifying randomization, although one-third of center and 40% of surgeon stratified trials did not also adjust analysis. CONCLUSION: Considerations for surgical learning and clustering effects are often unclear. Methods are varied and demonstrate poor adherence to established reporting guidelines. It is recommended that researchers consider these issues on a trial-by-trial basis, and report methods or justify where not needed to inform interpretation of results.

Nerve root block versus surgery (NERVES) for the treatment of radicular pain secondary to a prolapsed intervertebral disc herniation: study protocol for a multi-centre randomised controlled trial.

BACKGROUND: Sciatica is a common condition reported to affect over 3% of the UK population at any time and is often caused by a prolapsed intervertebral disc (PID). Although the duration and severity of symptoms can vary, pain persisting beyond 6 weeks is unlikely to recover spontaneously and may require investigation and treatment. Currently, there is no specific care pathway for sciatica in the National Health Service (NHS), and no direct comparison exists between surgical microdiscectomy and transforaminal epidural steroid injection (TFESI). The NERVES (NErve Root block VErsus Surgery) trial aims to address this by comparing clinical and cost-effectiveness of surgical microdiscectomy and TFESI to treat sciatica secondary to a PID. METHODS/DESIGN: A total of 163 patients were recruited from NHS out-patient clinics across the UK and randomised to either microdiscectomy or TFESI. Adult patients (aged 16-65 years) with sciatic pain endured for between 6 weeks and 12 months are eligible if their symptoms have not been improved by at least one form of conservative (non-operative) treatment and they are willing to provide consent. Patients will be excluded if they present with neurological deficit or have had previous surgery at the same level. The primary outcome is patient-reported disability measured using the Oswestry Disability Questionnaire (ODQ) score at 18 weeks post randomisation and secondary outcomes include disability and pain scales using numerical pain ratings, modified Roland-Morris and Core Outcome Measures Index at 12-weekly intervals, and patient satisfaction at 54 weeks. Cost-effectiveness and quality of life (QOL) will be assessed using the EQ-5D-5 L and self-report cost data at 12-weekly intervals and Hospital Episode Statistics (HES) data. Adverse event data will be collected. Analysis will follow the principle of intention-to-treat. DISCUSSION: NERVES is the first trial to evaluate the comparative clinical and cost-effectiveness of microdiscectomy to local anaesthetic and steroid administered via TFESI. The results of this research may facilitate the development of an evidence-based treatment strategy for patients with sciatica. TRIAL REGISTRATION: ISRCTN, ID: ISRCTN04820368 . Registered on 5 June 2014. EudraCT EudraCT2014-002751-25. Registered on 8 October 2014.

Is tonsillectomy mandatory for asymmetric tonsils in children? A review of our diagnostic tonsillectomy practice and the literature.

INTRODUCTION: Diagnostic tonsillectomy is performed to exclude malignancy. It is associated with a post-operative hemorrhage rate of 3.5%, (1) which is more dangerous in small children. No previous case series for asymmetrical tonsils have detected tonsil lymphoma.(2-6) We aimed to review our local diagnostic tonsillectomy practice. METHOD: The authors reviewed the clinical notes and histological results for all diagnostic tonsillectomies carried out from June 2013 to June 2016. RESULTS: We recorded data for 168 patients. There were four post-operative bleeds and one return to theatre. Bilateral tonsillectomies accounted for 152 operations (90.5%). Lymphoid hyperplasia accounted for 95% of histological diagnosis with no malignancies found. Pre-operative tonsil grading demonstrated no statistically significant association with histological tonsil weight difference (ANOVA p = 0.10). Actinomyces colonisation had little affect on tonsil weight difference when we compared patients with bilateral colonisation and no colonisation (t-test p = 0.540) and between tonsils in patients with unilateral tonsil Actinomyces colonisation (paired t-test p = 0.448). Recurrent tonsillitis was more prevalent in patients with Actinomyces colonisation than OSA/sleep disordered breathing (39% vs 15%). CONCLUSION: A literature search yielded five smaller case series of palatine tonsil asymmetry in children with no malignancy found.(2-6) Case-control studies report tonsillar asymmetry as the most common presenting symptom (73%) in tonsillar lymphoma.(7) This enlargement usually occurs rapidly within 6 weeks with new obstructive or systemic B-type symptoms.(3) A Turkish epidemiological study found asymmetrical tonsils in 1.7% of the healthy paediatric population.(8) We therefore estimate there to be over 210,000 children with asymmetrical tonsils in the UK. With an unreliable grading system, we believe asymmetrical tonsils in isolation, unchanged for over 6 weeks may not warrant tonsillectomy.

The BBaRTS Healthy Teeth Behaviour Change Programme for preventing dental caries in primary school children: study protocol for a cluster randomised controlled trial.

BACKGROUND: Oral health behaviours such as establishing twice-daily toothbrushing and sugar control intake need parental self-efficacy (PSE) to prevent the development of childhood dental caries. A previous study has shown that behaviour change techniques (BCTs) delivered via a storybook can improve parental self-efficacy to undertake twice-daily toothbrushing. OBJECTIVE: to determine whether an intervention (BBaRTS, Bedtime Brush and Read Together to Sleep), designed to increase PSE; delivered through storybooks with embedded BCTs, parenting skills and oral health messages, can improve child oral health compared to (1) an exactly similar intervention containing no behaviour change techniques, and (2) the BBaRTS intervention supplemented with home supply of fluoride toothpaste and supervised toothbrushing on schooldays. METHODS/DESIGN: A 2-year, three-arm, multicentre, cluster randomised controlled trial. PARTICIPANTS: children (estimated 2000-2600) aged 5-7 years and their families from 60 UK primary schools. INTERVENTION: Test group 1: a series of eight children's storybooks developed by a psychologist, public health dentist, science educator, children's author and illustrators, with guidance from the Department for Education (England). The books feature animal characters and contain embedded dental health messages, parenting skills and BCTs to promote good oral health routines focused on controlling sugar intake and toothbrushing, as well as reading at bedtime. Books are given out over 2 years. Test group 2: as Test group 1 plus home supplies of fluoride toothpaste (1000 ppmF), and daily supervised toothbrushing in school on schooldays. Active Control group: series of eight books with exactly the same stories, characters and illustrations, but without BCTs, dental health messages or parenting skills. Annual child dental examinations and parental questionnaires will be undertaken. A sub-set of participants will be invited to join an embedded study of the child's diet and salivary microbiota composition. PRIMARY OUTCOME MEASURE: dental caries experience in permanent teeth at age 7-8 years. DISCUSSION: A multi-disciplinary team was established to develop the BBaRTS Children's Healthy Teeth Programme. The books were developed in partnership with the Department for Education (England), informed by a series of focus groups with children, teachers and parents. TRIAL REGISTRATION: ISRCTN21461006 (date of registration 23 September 2015).

Postoperative infections following colorectal surgery in an English teaching hospital.

A retrospective case note review of postoperative infections within 30 days of colorectal surgery was completed. Surgical site infections (SSIs) were identified in 22% of patients (84/378), with other infections, e.g. urinary tract infections, identified in 18.3% of patients. SSIs, urinary and respiratory tract infections were all associated with increased durations of hospital admission compared with non-infected patients. Consideration should be given to postoperative surveillance for all infections, using antibiotic consumption as an objective outcome measure. Nine percent of patients developed an organ space SSI. Organ space SSIs were associated with the longest additional duration of hospital admission (15.5 days) and were the only infection associated with an increase in mortality at 1 year; 37% (13/35) mortality with an organ space SSI vs 4% (8/225) without an infection (odds ratio = 16, 95% confidence interval = 6, 43). Further research to prevent and treat organ space SSIs should be prioritized.

Assessing the association between oral hygiene and preterm birth by quantitative light-induced fluorescence.

The aim of this study was to investigate the purported link between oral hygiene and preterm birth by using image analysis tools to quantify dental plaque biofilm. Volunteers (n = 91) attending an antenatal clinic were identified as those considered to be "at high risk" of preterm delivery (i.e., a previous history of idiopathic preterm delivery, case group) or those who were not considered to be at risk (control group). The women had images of their anterior teeth captured using quantitative light-induced fluorescence (QLF). These images were analysed to calculate the amount of red fluorescent plaque (ΔR%) and percentage of plaque coverage. QLF showed little difference in ΔR% between the two groups, 65.00% case versus 68.70% control, whereas there was 19.29% difference with regard to the mean plaque coverage, 25.50% case versus 20.58% control. A logistic regression model showed a significant association between plaque coverage and case/control status (P = 0.031), controlling for other potential predictor variables, namely, smoking status, maternal age, and body mass index (BMI).