Comparison of Health Examination Survey Methods in Brazil, Chile, Colombia, Mexico, England, Scotland, and the United States.

Comparability of population surveys across countries is key to appraising trends in population health. Achieving this requires deep understanding of the methods used in these surveys to examine the extent to which the measurements are comparable. In this study, we obtained detailed protocols of 8 nationally representative surveys from 2007-2013 from Brazil, Chile, Colombia, Mexico, the United Kingdom (England and Scotland), and the United States-countries that that differ in economic and inequity indicators. Data were collected on sampling frame, sample selection procedures, recruitment, data collection methods, content of interview and examination modules, and measurement protocols. We also assessed their adherence to the World Health Organization's "STEPwise Approach to Surveillance" framework for population health surveys. The surveys, which included half a million participants, were highly comparable on sampling methodology, survey questions, and anthropometric measurements. Heterogeneity was found for physical activity questionnaires and biological samples collection. The common age range included by the surveys was adults aged 18-64 years. The methods used in these surveys were similar enough to enable comparative analyses of the data across the 7 countries. This comparability is crucial in assessing and comparing national and subgroup population health, and to assisting the transfer of research and policy knowledge across countries.

Combination of engineered Schwann cell grafts to secrete neurotrophin and chondroitinase promotes axonal regeneration and locomotion after spinal cord injury.

Transplantation of Schwann cells (SCs) is a promising therapeutic strategy for spinal cord repair. SCs introduced into lesions support axon regeneration, but because these axons do not exit the transplant, additional approaches with SCs are needed. Here, we transplanted SCs genetically modified to secrete a bifunctional neurotrophin (D15A) and chondroitinase ABC (ChABC) into a subacute contusion injury in rats. We examined the effects of these modifications on graft volume, SC number, degradation of chondroitin sulfate proteoglycans (CSPGs), astrogliosis, SC myelination of axons, propriospinal and supraspinal axon numbers, locomotor outcome (BBB scoring, CatWalk gait analysis), and mechanical and thermal sensitivity on the hind paws. D15A secreted from transplanted SCs increased graft volume and SC number and myelinated axon number. SCs secreting ChABC significantly decreased CSPGs, led to some egress of SCs from the graft, and increased propriospinal and 5-HT-positive axons in the graft. SCs secreting both D15A and ChABC yielded the best responses: (1) the largest number of SC myelinated axons, (2) more propriospinal axons in the graft and host tissue around and caudal to it, (3) more corticospinal axons closer to the graft and around and caudal to it, (4) more brainstem neurons projecting caudal to the transplant, (5) increased 5-HT-positive axons in the graft and caudal to it, (6) significant improvement in aspects of locomotion, and (7) improvement in mechanical and thermal allodynia. This is the first evidence that the combination of SC transplants engineered to secrete neurotrophin and chondroitinase further improves axonal regeneration and locomotor and sensory function.

Overall Survival, Disease-Free Survival, Local Recurrence, and Nipple-Areolar Recurrence in the Setting of Nipple-Sparing Mastectomy: A Meta-Analysis and Systematic Review.

BACKGROUND: Nipple-sparing mastectomy (NSM) is an increasingly common procedure; however, concerns exist regarding its oncological safety due to the potential for residual breast tissue to harbor occult malignancy or future cancer. METHODS: A systematic literature review was performed. Studies with internal comparison arms evaluating therapeutic NSM versus skin-sparing mastectomy (SSM) and/or modified radical mastectomy (MRM) were included in a meta-analysis of overall survival (OS), disease-free survival (DFS), and local recurrence (LR). Studies lacking comparison arms were only included in the systematic review to evaluate mean OS, DFS, LR, and nipple-areolar recurrence (NAR). RESULTS: The search yielded 851 articles. Twenty studies with 5594 patients met selection criteria. The meta-analysis included eight studies with comparison arms. Seven studies that compared OS found a 3.4% risk difference between NSM and MRM/SSM, five studies that compared DFS found a 9.6% risk difference between NSM and MRM/SSM, and eight studies that compared LR found a 0.4% risk difference between NSM and MRM/SSM. Risk differences for all outcomes were not statistically significant. The systematic review included all 20 studies and evaluated OS, DFS, LR, and NAR. Studies with follow-up intervals of <3 years, 3-5 years, and >5 years had mean OS of 97.2, 97.9, and 86.8%; DFS of 93.1, 92.3, and 76.1%; LR of 5.4, 1.4, and 11.4%; and NAR of 2.1, 1.0, and 3.4%, respectively. CONCLUSIONS: This study did not detect adverse oncologic outcomes of NSM in carefully selected women with early-stage breast cancer. Use of prospective data registries, notably the Nipple-Sparing Mastectomy Registry, will add clarity to this important clinical question.

Scoring the Icecap-a capability instrument. Estimation of a UK general population tariff.

This paper reports the results of a best-worst scaling (BWS) study to value the Investigating Choice Experiments Capability Measure for Adults (ICECAP-A), a new capability measure among adults, in a UK setting. A main effects plan plus its foldover was used to estimate weights for each of the four levels of all five attributes. The BWS study was administered to 413 randomly sampled individuals, together with sociodemographic and other questions. Scale-adjusted latent class analyses identified two preference and two (variance) scale classes. Ability to characterize preference and scale heterogeneity was limited, but data quality was good, and the final model exhibited a high pseudo-r-squared. After adjusting for heterogeneity, a population tariff was estimated. This showed that 'attachment' and 'stability' each account for around 22% of the space, and 'autonomy', 'achievement' and 'enjoyment' account for around 18% each. Across all attributes, greater value was placed on the difference between the lowest levels of capability than between the highest. This tariff will enable ICECAP-A to be used in economic evaluation both within the field of health and across public policy generally.

Using longitudinal data from the Health Survey for England to resolve discrepancies in thresholds for haemoglobin in older adults.

Anaemia increases with age and is common among older people. Due to its relationship with morbidity and mortality, accurate diagnosis is important. Thresholds defining the diagnosis of anaemia have been the subject of considerable scientific debate, with both higher and lower cut-offs proposed. High haemoglobin is also a health risk in some but not all studies. Using nationally representative data of 5,329 adults aged 65 + years (Health Survey for England 1998, 2005, 2006), linked to administrative mortality data, this paper describes the relationship between haemoglobin levels and mortality, adjusted for age and other confounders. Among men, a reverse J shaped relationship was observed: relative to the modal group (140-149 g/l), those with 'mild anaemia' of 120-129 g/l haemoglobin had a 56% (95% confidence interval 24-96%) greater mortality hazard, and those with 'severe anaemia', haemoglobin <120 g/l, had an 87% (39-153%) greater hazard. At the other end of the range, those with haemoglobin ≥160 g/l had 32% (2-70%) greater mortality hazard. Haemoglobin levels in women showed a similar but smaller, non-significant pattern: hazard ratio 1·32 (0·91-1·92) for severe anaemia (<110 g/l), and 1·30 (0·95-1·79) for high haemoglobin (≥150 g/l). This research supports the use of the World Health Organization thresholds (130 g/l for men, 120 g/l for women).

An investigation of the construct validity of the ICECAP-A capability measure.

PURPOSE: To investigate the construct validity of the ICECAP-A capability wellbeing measure. METHODS: A face-to-face interview-administered survey was conducted with 418 members of the UK general population, randomly sampled from the Postcode Address File. Pre-specified hypotheses were developed about the expected associations between individuals' ICECAP-A responses and their socio-economic circumstances, health and freedom. The hypotheses were investigated using statistical tests of association. RESULTS: The ICECAP-A responses and scores reflected differences across different health and socioeconomic groups as anticipated, but did not distinguish individuals by the level of local deprivation. Mean ICECAP-A scores reflected individuals' perceived freedom slightly more closely than did measures of health and happiness. CONCLUSION: This study suggests that the ICECAP-A measure can identify expected differences in capability wellbeing in a general population sample. Further work could establish whether self-reported capabilities exhibit desirable validity and acceptability in sub-groups of the population such as patients, social care recipients and informal carers.

A diagnostic dilemma: differentiating between granulomatosis with polyangiitis and tuberculosis.

Granulomatosis with polyangiitis (GPA, formerly Wegener's granulomatosis) can present diagnostic difficulties for the clinician as there can be considerable overlap in features with tuberculosis (TB). Indeed, there are documented cases both of coexisting TB and GPA, and cases wrongly diagnosed as GPA when in fact TB was the underlying diagnosis. This lesson presents a case of GPA where TB was also considered as a differential and highlights the diagnostic and management difficulties when this is the case.

Does the use of prediction equations to correct self-reported height and weight improve obesity prevalence estimates? A pooled cross-sectional analysis of Health Survey for England data.

OBJECTIVE: Adults typically overestimate height and underestimate weight compared with directly measured values, and such misreporting varies by sociodemographic and health-related factors. Using self-reported and interviewer-measured height and weight, collected from the same participants, we aimed to develop a set of prediction equations to correct bias in self-reported height and weight and assess whether this adjustment improved the accuracy of obesity prevalence estimates relative to those based only on self-report. DESIGN: Population-based cross-sectional study. PARTICIPANTS: 38 940 participants aged 16+ (Health Survey for England 2011-2016) with non-missing self-reported and interviewer-measured height and weight. MAIN OUTCOME MEASURES: Comparisons between self-reported, interviewer-measured (gold standard) and corrected (based on prediction equations) body mass index (BMI: kg/m2) including (1) difference between means and obesity prevalence and (2) measures of agreement for BMI classification. RESULTS: On average, men overestimated height more than women (1.6 cm and 1.0 cm, respectively; p<0.001), while women underestimated weight more than men (2.1 kg and 1.5 kg, respectively; p<0.001). Underestimation of BMI was slightly larger for women than for men (1.1 kg/m2 and 1.0 kg/m2, respectively; p<0.001). Obesity prevalence based on BMI from self-report was 6.8 and 6.0 percentage points (pp) lower than that estimated using measured BMI for men and women, respectively. Corrected BMI (based on models containing all significant predictors of misreporting of height and weight) lowered underestimation of obesity to 0.8pp in both sexes and improved the sensitivity of obesity over self-reported BMI by 15.0pp for men and 12.2pp for women. Results based on simpler models using age alone as a predictor of misreporting were similar. CONCLUSIONS: Compared with self-reported data, applying prediction equations improved the accuracy of obesity prevalence estimates and increased sensitivity of being classified as obese. Including additional sociodemographic variables did not improve obesity classification enough to justify the added complexity of including them in prediction equations.

Sex differences in the secular change in waist circumference relative to body mass index in the Americas and England from 1997 to 2020.

Objective: To quantify changes over time in waist circumference (WC) relative to body mass index (BMI) by sex in the Americas (United States of America, Mexico, Chile, Peru) and England. Methods: Data from adults aged 25-64 years between 1997 and 2020 was analysed; US data was stratified by racial-ethnic groups. Sex-specific BMI and WC means, and obesity and abdominal obesity prevalence, were compared between the first and last surveys. Using data from all survey years, secular changes across the BMI and WC distributions were estimated applying quantile regression models. BMI was added as a predictor of WC to estimate secular changes in WC relative to BMI. Interaction terms were included in all models to evaluate differences by sex. Results: BMI and WC (except Peru) showed larger secular increases at the upper-tails of the distributions in both sexes. Increases at the 50th and 75th WC centiles relative to BMI were more pronounced in women than in men, with larger increases in US non-Hispanic whites and in England. In men, increases in WC independently of BMI were most evident in Mexico. Conclusions: Disease risk associated with visceral fat, is potentially underestimated by national surveillance efforts that quantify secular changes only in BMI.

Associations between indoor temperature, self-rated health and socioeconomic position in a cross-sectional study of adults in England.

OBJECTIVE: Excess winter deaths are a major public health concern in England and Wales, with an average of 20 000 deaths per year since 2010. Feeling cold at home during winter is associated with reporting poor general health; cold and damp homes have greater prevalence in lower socioeconomic groups. Overheating in the summer also has adverse health consequences. This study evaluates the association between indoor temperature and general health and the extent to which this is affected by socioeconomic and household factors. DESIGN: Cross-sectional study. SETTING: England. PARTICIPANTS: Secondary data of 74 736 individuals living in England that took part in the Health Survey for England (HSE) between 2003 and 2014. The HSE is an annual household survey which uses multilevel stratification to select a new, nationally representative sample each year. The study sample comprised adults who had a nurse visit; the analytical sample was adults who had observations for indoor temperature and self-rated health. RESULTS: Using both logistic and linear regression models to examine indoor temperature and health status, adjusting for socioeconomic and housing factors, the study found an association between poor health and higher indoor temperatures. Each one degree increase in indoor temperature was associated with a 1.4% (95% CI 0.5% to 2.3%) increase in the odds of poor health. After adjusting for income, education, employment type, household size and home ownership, the OR of poor health for each degree temperature rise increased by 19%, to a 1.7% (95% CI 0.7% to 2.6%) increase in odds of poor health with each degree temperature rise. CONCLUSION: People with worse self-reported health had higher indoor temperatures after adjusting for household factors. People with worse health may have chosen to maintain warmer environments or been advised to. However, other latent factors, such as housing type and energy performance could have an effect.

'My blood pressure is low today, do you have the heating on?' The association between indoor temperature and blood pressure.

OBJECTIVES: The independent association of indoor temperature with blood pressure (BP) is poorly understood and is not routinely considered in hypertension diagnosis or research. Questions remain as to whether the effect of indoor temperature on BP is confounded or modified by other factors. METHODS: This study used data from the Health Survey for England 2014, consisting of 4659 community-dwelling adults aged 16 years and over, interviewed from January to December. Multivariable regression models were used to determine whether indoor temperature was related to levels of BP, and whether these relationships were confounded by other factors, including mean monthly outdoor temperature. RESULTS: After controlling for confounding variables, a 1°C decrease in indoor temperature was associated with rises of 0.48 mmHg (95% confidence interval: -0.72 to -0.25) in SBP and 0.45 mmHg (95% confidence interval: -0.63 to -0.27) in DBP. The magnitude of association of indoor temperature with DBP and SBP was modified by physical activity. The indoor temperature-BP relationship was stronger in people who do not take physical activity regularly than people who exercise regularly. CONCLUSION: The size of the independent association between indoor temperature and BP suggests it should be considered in the clinical management of hypertension and in hypertension research. Room temperature should also be considered as a modifiable risk factor in hypertension-related mortality and morbidity.

Has the UK Healthy Start voucher scheme been associated with an increased fruit and vegetable intake among target families? Analysis of Health Survey for England data, 2001-2014.

BACKGROUND: Healthy Start (HS) is a UK government programme, introduced in 2006, providing vouchers to pregnant women or families with children aged <4 who are in receipt of certain benefits. Vouchers can be exchanged for fruit and vegetables (F&V), milk or infant formula. We sought to identify any association between HS and F&V intake. METHODS: We analysed repeated cross-sectional data from the Health Survey for England. Study participants were classified into one of four groups: one HS-eligible group and three control groups, meeting only the income or demographic or no eligibility criterion. Outcome measures were mean F&V intake and the proportions of participants consuming ≥3 and ≥1 portion/day. Outcomes were compared across the four groups over four time periods: 2001-2003, 2004-2006, 2007-2009 and 2010-2014. Regression analyses examined whether F&V intake among HS-eligible participants had a significantly different rate of change from those in the control groups. RESULTS: The change in mean F&V consumption over time was similar in HS-eligible adults and children to that of the control groups. Likewise, the change in odds of consuming ≥3 or ≥1 portion of F&V/day over time was similar among HS-eligible participants and control groups. CONCLUSION: This study found that during the period 2001-2003 to 2010-2014, F&V consumption among adults and children in households deemed eligible for HS changed similarly to that of other adults and children. Potential explanations include that vouchers may have been spent on milk or infant formula, or that vouchers helped protect F&V consumption in low-income households.

Social inequalities in prevalence of diagnosed and undiagnosed diabetes and impaired glucose regulation in participants in the Health Surveys for England series.

OBJECTIVES: To ascertain the extent of socioeconomic and health condition inequalities in people with diagnosed and undiagnosed diabetes and impaired glucose regulation (IGR) in random samples of the general population in England, as earlier diagnosis of diabetes and treatment of people with IGR can reduce adverse sequelae of diabetes. Various screening instruments were compared to identify IGR, in addition to undiagnosed diabetes. DESIGN: 5, annual cross-sectional health examination surveys; data adjusted for complex survey design. SETTING: Random selection of private homes across England, new sample annually 2009-2013. PARTICIPANTS: 5, nationally representative random samples of the general, free-living population: ≥ 1 adult interviewed in 24,254 of 36,889 eligible addresses selected. 18,399 adults had a valid glycated haemoglobin (HbA1c) measurement and answered the diabetes questions. MAIN OUTCOME MEASURES: Diagnosed diabetes, undiagnosed diabetes (HbA1c ≥ 48 mmol/mol), IGR (HbA1c 42-47 mmol/mol). RESULTS: Overall, 11% of the population had IGR, 2% undiagnosed and 6% diagnosed diabetes. Age-standardised prevalence was highest among Asian (19% (95% CI 16% to 23%), 3% (2% to 5%) and 12% (9% to 16%) respectively) and black participants (17% (13% to 21%), 2% (1% to 4%) and 14% (9% to 20%) respectively). These were also higher among people with lower income, less education, lower occupational class and greater deprivation. Education (OR 1.49 (95% CI 1.27 to 1.74) for no qualifications vs degree or higher) and income (1.35 (1.12 to 1.62) for lowest vs highest income quintile) remained significantly associated with IGR or undiagnosed diabetes on multivariate regression. The greatest odds of IGR or undiagnosed diabetes were with increasing age over 34 years (eg, OR 18.69 (11.53 to 30.28) aged 65-74 vs 16-24). Other significant associations were ethnic group (Asian (3.91 (3.02 to 5.05)), African-American (2.34 (1.62 to 3.38)) or 'other' (2.04 (1.07 to 3.88)) vs Caucasian); sex (OR 1.32(1.19 to 1.46) for men vs women); body mass index (3.54 (2.52 to 4.96) for morbidly obese vs not overweight); and waist circumference (2.00 (1.67 to 2.38) for very high vs low). CONCLUSIONS: Social inequalities in hyperglycaemia exist, additional to well-known demographic and anthropometric risk factors for diabetes and IGR.

Immediate pedicled gracilis flap in radial forearm flap phalloplasty for transgender male patients to reduce urinary fistula.

BACKGROUND AND AIM: Radial forearm phalloplasty is accompanied by high rates of fistula formation. We examined the effect of placing a pedicled gracilis myofascial flap around the urethral anastomosis at the time of radial forearm flap transfer on the development of postoperative urethrocutaneous fistula. METHODS: Fifteen patients underwent phalloplasty with urethroplasty between June 2012 and October 2015, and they met the inclusion and exclusion criteria for the study. We retrospectively reviewed patients' medical records and extracted patient demographic data, prelamination technique used (mucosa, skin graft, both, or neither), and whether or not a gracilis myofascial flap was harvested at the time of flap transfer and used to reinforce the native-neourethral anastomosis. The chi-squared test was used to evaluate the association between the presence of a gracilis flap and fistula formation. RESULTS: Four patients received a gracilis flap as part of their primary phalloplasty operation. None of these patients developed a fistula. Eleven patients did not receive a gracilis flap at the time of initial surgery and seven developed a fistula. DISCUSSION: In our patient series, inclusion of a pedicled myofascial gracilis flap at the time of radial forearm phalloplasty with urethroplasty was associated with an absence of fistula formation. Therefore, we have since made inclusion of this flap a standard practice for all transmales undergoing phalloplasty with urethroplasty.

Impaired glucose metabolism among those with and without diagnosed diabetes and mortality: a cohort study using Health Survey for England data.

BACKGROUND: The extent that controlled diabetes impacts upon mortality, compared with uncontrolled diabetes, and how pre-diabetes alters mortality risk remain issues requiring clarification. METHODS: We carried out a cohort study of 22,106 Health Survey for England participants with a HbA1C measurement linked with UK mortality records. We estimated hazard ratios (HRs) of all-cause, cancer and cardiovascular disease (CVD) mortality and 95% confidence intervals (CI) using Cox regression. RESULTS: Average follow-up time was seven years and there were 1,509 deaths within the sample. Compared with the non-diabetic and normoglycaemic group (HbA1C <5.7% [<39 mmol/mol] and did not indicate diabetes), undiagnosed diabetes (HbA1C ≥6.5% [≥48 mmol/mol] and did not indicate diabetes) inferred an increased risk of mortality for all-causes (HR 1.40, 1.09-1.80) and CVD (1.99, 1.35-2.94), as did uncontrolled diabetes (diagnosed diabetes and HbA1C ≥6.5% [≥48 mmol/mol]) and diabetes with moderately raised HbA1C (diagnosed diabetes and HbA1C 5.7-<6.5% [39-<48 mmol/mol]). Those with controlled diabetes (diagnosed diabetes and HbA<5.7% [<39 mmol/mol]) had an increased HR in relation to mortality from CVD only. Pre-diabetes (those who did not indicate diagnosed diabetes and HbA1C 5.7-<6.5% [39-<48 mmol/mol]) was not associated with increased mortality, and raised HbA1C did not appear to have a statistically significant impact upon cancer mortality. Adjustment for BMI and socioeconomic status had a limited impact upon our results. We also found women had a higher all-cause and CVD mortality risk compared with men. CONCLUSIONS: We found higher rates of all-cause and CVD mortality among those with raised HbA1C, but not for those with pre-diabetes, compared with those without diabetes. This excess differed by sex and diabetes status. The large number of deaths from cancer and CVD globally suggests that controlling blood glucose levels and policies to prevent hyperglycaemia should be considered public health priorities.

Estimating population prevalence of potential airflow obstruction using different spirometric criteria: a pooled cross-sectional analysis of persons aged 40-95†years in England and Wales.

OBJECTIVES: Consistent estimation of the burden of chronic obstructive pulmonary disease (COPD) has been hindered by differences in methods, including different spirometric cut-offs for impaired lung function. The impact of different definitions on the prevalence of potential airflow obstruction, and its associations with key risk factors, is evaluated using cross-sectional data from two nationally representative population surveys. DESIGN: Pooled cross-sectional analysis of Wave 2 of the UK Household Longitudinal Survey and the Health Survey for England 2010, including 7879 participants, aged 40-95 years, who lived in England and Wales, without diagnosed asthma and with good-quality spirometry data. Potential airflow obstruction was defined using self-reported physician-diagnosed COPD; a fixed threshold (FT) forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) ratio <0.7 and an age-specific, sex-specific, height-specific and ethnic-specific lower limit of normal (LLN). Standardised questions elicited self-reported information on demography, smoking history, ethnicity, occupation, respiratory symptoms and cardiovascular disease. RESULTS: Consistent across definitions, participants classed with obstructed airflow were more likely to be older, currently smoke, have higher pack-years of smoking and be engaged in routine occupations. The prevalence of airflow obstruction was 2.8% (95% CI 2.3% to 3.2%), 22.2% (21.2% to 23.2%) and 13.1% (12.2% to 13.9%) according to diagnosed COPD, FT and LLN, respectively. The gap in prevalence between FT and LLN increased in older age groups. Sex differences in the risk of obstruction, after adjustment for key risk factors, was sensitive to the choice of spirometric cut-off, being significantly higher in men when using FT, compared with no significant difference using LLN. CONCLUSIONS: Applying FT or LLN spirometric cut-offs gives a different picture of the size and distribution of the disease burden. Longitudinal studies examining differences in unscheduled hospital admissions and risk of death between FT and LLN may inform the choice as to the best way to include spirometry in assessments of airflow obstruction.

Nasal levels of nitric oxide as an outcome variable in allergic upper respiratory tract disease: Influence of atopy and hayfever on nNO.

BACKGROUND: The role of nasal levels of nitric oxide (nNO) as noninvasive marker of inflammation and as an outcome variable in allergic upper respiratory tract disease has not been defined. Our aim is to determine in patients with perennial allergic rhinitis (i) whether nNO is elevated, (ii) whether increased nNO is correlated with upper respiratory tract symptoms (discrimination), and (iii) whether changes in symptom scores are associated with changes in nNO levels (responsiveness). METHODS: Subjects (n = 38) with perennial rhinitis were studied weekly for 3 weeks. At each visit they completed a validated symptom questionnaire and had expired NO and nNO measured. RESULTS: Nasal NO levels were higher in those allergic to house-dust mite and cat. Nasal NO levels in subjects with perennial rhinitis were not elevated compared with non-atopic asymptomatic subjects. The intra-week reproducibility of nNO measurements was poor. There was no relationship between the symptom scores and nasal NO levels (discrimination). When analysis was confined to nasal symptoms, a weak but negative correlation was identified. Changes in symptom scores from week to week were not correlated with changes in nNO levels (responsiveness). CONCLUSIONS: Nasal NO levels were not elevated in subjects with perennial rhinitis, and nNO levels were neither discriminatory nor responsive. The measurement of nNO therefore appears not to be a useful marker of disease activity in subjects with allergic rhinitis.