Natural Experiment Approach Research Articles

Catastrophic supply chain disruptions and supply network changes: a study of the 2011 Japanese earthquake

PurposeCatastrophic supply chain disruptions can significantly damage the operational and financial performance of firms. While a growing body of literature on supply network structures has studied what influences supply networks' vulnerability to supply chain disruptions and capability to recover from them, it remains unclear how supply network structures change after major supply chain disruptions. We aim to provide an understanding of how these changes occur.Design/methodology/approachUsing a natural experiment approach and supply network data from Factset, this study investigates how firms' supply network structures change after experiencing the catastrophic supply chain disruptions caused by the 2011 Tohoku earthquake and tsunami in Japan. We capture post-earthquake supply network changes using the measures of degree centrality and ego network density.FindingsThe results of the analysis suggest that compared to unaffected firms, the affected firms experience changes in their supply network structures tending toward lower complexity measured by in-degree centrality, out-degree centrality and ego network density.Originality/valueThis study contributes to social network theory and the complex adaptive supply network literature by providing empirical evidence of structural changes in supply networks after catastrophic supply chain disruptions. A managerial contribution is made by providing a reflection on why these changes might be occurring and alert firms to the challenges of managing complexity in their supply networks.

Geographic market size and low bid competitiveness in construction companies

PurposeThe purpose of this study is to determine the relationship between the geographic market size of businesses and the competitiveness of being able to bid at low prices.Design/methodology/approachThe design of this study is based on a natural experiment approach. Firstly, after controlling for the firm size and other factors, the author sees that firms participating in bidding in a large region are more competitive to bid at lower prices than firms doing business in a smaller region. The author then tests for causality in a natural experiment of the exogenous event.FindingsThe results show that firms participating in the bidding process in a large area are more competitive to bid at lower prices than firms doing business in a small area. This is tested in a natural experiment, and the result is that they are more competitive because they do business in a larger area.Practical implicationsThe practical implication is that, when aiming for competitiveness, it is most important to consider the nature of the business and to see the essence of the business, for example, that networks are important in the construction industry, and that doing business over a wide area is the way to become competitive.Social implicationsThe social implications are that to make firms more competitive, we must look at the characteristics of the industry and come up with policies that fit the reality, such as encouraging them to do business in a wide area.Originality/valueThe originality of this study is that this study viewed competitiveness as being able to bid low prices for public procurement and found that doing business in a wide area is competitive. Furthermore, the causal effect of the study was to test the fact that doing business in a wide area does not mean doing business in a wide area because it is competitive, but that doing business in a wide area creates a competitive advantage.

College Football Referee Bias and Sports Betting Impact

Conferences entrust college football referees to impartially officiate games. However, a growing body of research documents officiating biases in sports. We focus on bias among major college football referees. Following a natural experiment approach, we contrast in-conference games with a quasi-control group consisting of games involving teams from different conferences. Specifically, we find significant relationships between the betting line variables—expected game closeness and clear game favorite—and penalties among ACC and former Big East officials that suggests bias toward the underdog team during in-conference games. Additionally, we find home field bias in the ACC and Big XII and bias of game pace in the Big XII and former Big East. We also do a preliminary examination of the biases’ roots. Some biases we pinpoint are, counterintuitively, revenue-inhibiting for certain conferences. Our results show the potential impact on-field referees have on games and the underlying revenue streams for the conferences. They also highlight oft-discussed, but rarely researched, officiating biases at the intersection of game integrity and the commercial goals of the competing programs and the conferences they represent. To lessen such friction, we advocate for centralization of the management and oversight of college football referees. We conclude by explaining how such biases could impact expanded legalized sports betting after the US Supreme Court removed restrictions on state-by-state regulation in 2018.

Dose-response effect of a large-scale greenway intervention on physical activities: The first natural experimental study in China.

Although many cross-sectional studies have confirmed the positive associations between greenspaces and physical activity, evidence from natural experiments is scarce, especially for large-scale greenspace interventions. In addition, it is unclear how the physical-activity-related benefits of a greenspace intervention vary with distance from residences to greenspaces. We used a natural experimental approach to explore the impact on physical activity of a large-scale greenway intervention, namely the East Lake greenway, in Wuhan, China. Two waves of survey data (before and after the intervention in 2016 and 2019, respectively) were collected from 1020 participants residing in 52 neighbourhoods at different distances (0-1, 1-2, 2-3, 3-4, and 4-5km) from the 102-km-long greenway. The results obtained using difference-in-difference models indicated that the greenway intervention had positive effects on both moderate-to-vigorous physical activity (MVPA) and overall physical activity (MET-minutes/week) after controlling for individual and neighbourhood covariates. Furthermore, the physical activity benefits of the greenway intervention were found to decrease with increasing distance between the greenway and the participants' residences. Individuals living closer to this large-scale greenway accrued more substantial physical activity benefits. Our results, together with those of other natural experimental studies, suggest that large-scale greenspace interventions may provide long-term physical activity benefits to residents living in a wide geographic area.

Impact of Minimum Unit Pricing on Alcohol-Related Emergency Department Attendances in Scotland: A Natural Experiment Study

Background: Minimum Unit Pricing (MUP) was introduced in Scotland at 50p per unit (8g) of alcohol on 1st May 2018 to reduce alcohol consumption and associated harms. We assessed its impact on alcohol-related emergency department (ED) attendances, drinking patterns, and having an alcohol-related diagnosis amongst ED attendees. Methods: We used a natural experiment approach to compare outcomes between Scotland (intervention group) and England (comparison group). Two EDs in Scotland and two in England were recruited for one baseline and two post-intervention waves. Research nurses considered all attendees for interview, and recorded reasons for not interviewing attendees. The primary outcome was alcohol-related attendances among all recorded attendees. Secondary outcomes included alcohol-related diagnosis, binge drinking and high-risk drinking, and tested for differential effects across socioeconomic groups. Difference-in-difference regression models adjusted for age, sex and baseline covariates. Findings: 12,207 participants were recruited in Scotland and 11,248 in England. The odds ratio for an alcohol-related attendance was 1.14 (95% CI 0.90-1.44) after the introduction of MUP in Scotland relative to England, after controlling for covariates. It is estimated that an additional 1.0% (95% CI -0.7% to 2.7%) of the ED attendances were alcohol-related than would have been the case in the absence of MUP. Meanwhile, the odds for an attendee having at least one alcohol-related diagnosis increased after MUP (OR=1.25, 95%CI 1.00-1.57). There was no evidence of substantive differences in the majority of other secondary outcomes after the introduction of MUP in Scotland, or of differential effects across socioeconomic groups. Interpretation: We found no evidence that MUP impacted on alcohol-related ED attendances.

The effect of implementing pre-surgical ultrasound-guided fine-needle aspiration biopsy on thyroid surgery, a 6-year interrupted time series analysis in Qilu Hospital of Shandong University

Thyroid fine-needle aspiration biopsy (FNAB) is not well developed in most of the large academic hospitals in China, including Qilu Hospital of Shandong University. Ultrasound-guided FNAB (UG-FNAB) was initiated as a pre-surgical diagnostic method in 2015 in Qilu Hospital, and the current study evaluates its impact on the number of thyroid surgeries and the ratio of malignancy (ROM) in surgically resected cases, comparing the post and pre-UG-FNAB periods. Thyroid surgery and UG-FNAB data for the study period (Jan 2013 to Dec 2018) were collected from the hospital information system (HIS). A natural experimental approach using segmented linear regression was performed on the interrupted time-series (ITS) data to estimate the level-change of the number and the trend-change of ROM of surgically resected cases following the implementation of UG-FNAB diagnosis. The number of UG-FNAB cases in Qilu Hospital increased rapidly from 1,367 in 2015 to 3,402 in 2018, with an average annual increase of 678 cases. Comparing the pre-UG-FNAB and post-UG-FNAB periods, the overall ROM of thyroid resections increased from 58.7% to 73.2% (P<0.01). Due to the implementation of UG-FNAB, the regression line of surgical cases showed an inflection point in March 2015, and the slope of the regression line of post-intervention was lower than that of pre-intervention. For each additional month, the ROM in thyroid surgical cases increased by 0.389% (P<0.01). After excluding the influence of time, the ROM in surgically resected thyroid cases increased by 4.781% due to the application of the UG-FNAB examination (P<0.01). This successful implementation of UG-FNAB further improved overall ROMs in surgically resected cases particularly as we acquired further experience with the procedure and reduced unnecessary diagnostic surgeries for patients with benign and borderline lesions.

30.M. Workshop: Experiences using a multi-methods study in an ethnic diverse deprived social housing area in Denmark

Abstract Structural changes are commonly used as a political tool to improve health and wellbeing and reduce health disparities in deprived social housing areas. However, the evidence of effect is limited and ambiguous. Potential consequences are both positive (increasing heterogeneity in socioeconomic background of residents, better overall health) and negative (poorer social cohesion, stress due to relocation of residents). In Denmark, a number of social housing areas have recently been selected for large structural changes based on a politically defined list of indicators related to the socio-economic status and ethnicity of the residents. The setting for the workshop is a prospective multi-methods study of health, wellbeing and social relations among residents in one of the selected social housing areas in the period 2015-2025 with a focus on middle-aged and older residents, 'Health, Well-being and Social Relations in a Changing Neighbourhood'. Twenty percent of the apartment blocks in the area will be demolished in the period 2019-2020. This study provides a unique opportunity to explore the effects of large-scale structural changes in a longitudinal and multi-methods perspective. Thus, the study aims to increase our understanding of how changes affect the health, well-being and social relations among residents from different perspectives. Through user engagement in the design of the study and in particular in the two co-created interventions embedded in the study design, a focus on empowerment and recognition of the resources and perspectives of residents is encouraged. The main objectives of this workshop is to present and discuss the advantages and challenges with the different methodological approaches and communicative tools and how to gain synergistic effects of this approach within the setting of the research project. The workshop will include five presentations followed by a discussion. A focus on the multiple methods employed in the project and how they interact and supplement each other will bind the presentations together. The purpose is to share and discuss with the public health research community the experienced advantages as well as challenges with this approach. The project includes: A three wave survey (before, during and after the structural changes) (target population N∼600 in each wave). A needs assessment based on 31 qualitative interviews and results from the first survey wave. Two co-created interventions with a main purpose of ensuring social cohesion in the community during the structural changes. Register-based information on health and social factors in the period 2015-2025 on all residents living in the social housing area as well as in a similar neighbouring control social housing area not undergoing structural changes until 2023 (natural experiment approach). Novel in this area, graphic illustrative methods will be included as an instrument for increasing communication success and as part of the interventions. Key messages The workshop offers insight on synergistic effects of a longitudinal, multi-methods study exploring health and social effects of large-scale structural changes in an ethnic diverse social housing area. Offers a discussion of the challenges with data collection in a period with Danish state level political decisions leading to significant structural changes in deprived social housing areas.

The effect of number of siblings and birth order on educational attainment: Empirical Evidence from Chinese General Social Survey

Data from China demonstrate that the effect of the number of siblings on education is restricted by many factors, such as children’s gender, urban or rural household registration, whether there is only one child, the birth order of children within the family, and parents’ status. Chinese families have significant preferences for the eldest son and the youngest son. Moreover, research based on the natural experiment and instrumental variable approach suggests that market-oriented reform of education has increased the cost of family education expenditures since China’s reform and opening up, which further aggravates the negative impact on education of having many siblings in an urban setting.

The COVID-19 Pandemic

The COVID-19 Pandemic

The effect of debt market imperfection on capital structure and investment: Evidence from the 2008 global financial crisis in Japan

This paper investigates how debt market frictions affect real firm behaviors such as capital structures and investments differently based on whether a firm has access to the public debt market, taking debt structure differences into account. To this aim, using the natural experimental approach to examine the 2008 credit supply shock in Japan, we show that firms without access to the public debt market face decreased leverage and investment, accompanied by decreased bank debt, compared to firms with access. Considering that firms without access to the public debt market are more dependent on banks for their debt and are likely to have closer relationships with banks than those with access, it is intriguing that bank-dependent firms face reduced debt supplies from banks compared to other firms. Moreover, through investigation of the regression of investments where the interaction term with different debt structures is introduced, it is suggested that differences in debt structure or debt maturity between firms with access to public debt and those without access also play an important role in determining debt and investment and that bank-dependent firms faced more underinvestment or uncertainty after the financial crisis of 2008 than firms with access to the public debt market.

PCN254 - TRENDS IN BRCA TESTING OVER TIME AND SOCIOECONOMIC DEPRIVATION

BRCA1&2 (BRCA) testing received much publicity following Angelina Jolie’s editorial ‘My Medical Choice’ in the New York Times on the 14th May 2013. In addition, in the UK, guidelines were updated by NICE (clinical guidance CG164) on the 25th June 2013. We analysed the effects of these two events on uptake of BRCA1 and BRCA2 testing in the area covered by Cheshire and Merseyside Regional Genetic Service, and whether this was affected by socioeconomic deprivation. A database was collated using routinely collected hospital data for patients who received hereditary breast and ovarian cancer (HBOC) BRCA testing. A total of 1393 patients received BRCA testing. A natural experimental approach was undertaken using segmented linear regression to estimate changes in the level and trend of BRCA testing following the publication of both the Jolie’s editorial and NICE CG164. Regression coefficients were used to calculate average change in rates, adjusted for prior level and trend. The Index of Multiple Deprivation (IMD) of patients from areas who received BRCA testing to those of the catchment population were compared. The month following the publication of Jolie’s editorial and NICE CG164, BRCA testing increased by approximately 84% (P=0.006). Between April 2010 and March 2017, testing rates increased 11-fold from 0.14 to 1.52 tests/100,000 per month. The odds of receiving BRCA testing were higher for patients from socioeconomically advantaged areas pre-publication (OR 1.21 95% CI 0.99-1.48, P=0.06) although this was not significant. After publication the odds were significantly higher for patients from advantaged areas compared with disadvantaged areas (OR 1.18 95% CI 1.08-1.29, P=0.0002). Our study found that BRCA testing uptake increased following the publication of Jolie’s editorial and NICE CG164. However, uptake was lower in more deprived areas. This inequity should be further investigated, and consideration given to targeted care within areas of greater socioeconomic deprivation.

Evaluating the Family Nurse Partnership Programme in Scotland: a natural experiment approach

IntroductionThe Family Nurse Partnership(FNP) is an intensive home-visiting service for teenage first-time mothers (and children), developed/trialled in the US and adapted/trialled across Europe.The Scottish Government(SG) aims to build on and supplement the existing national/international evidence base for FNP, to assess effectiveness and opportunities for optimisation of the programme, for future decision making in Scotland.&#x0D; Objectives and ApproachThe evaluation commissioned is a natural experiment of FNP, taking advantage of the existing information infrastructure in Scotland. This natural experiment represents an important opportunity to determine programme impact upon many key programme outcomes using routinely collected data at a lower cost than a comparably sized effectiveness trial. Key objectives are: to identify clients in receipt of FNP-support and a control sample of matched families who would meet criteria for FNP but did not receive support, to obtain approval and through anonymised data linkage link to health and other data, and to determine the effect of FNP across a range of maternal and child outcomes.&#x0D; ResultsThe succes of the natural experiment design in trying to replicate the gold standard design of the RCT will be presented and will cover the following topics: (how cases and a comparable group of first-time teenage women have been identified across 10 Health Boards (HBs) between 2009 and 2016 using data made available by the electronic Data Research and Innovation Service (eDRIS) from FNP, NHS Scotland and SG; the matching process of the cases and controls using propensity score methods to ensure an unbiased comparison; the linkage to health, social care and educational datasets and the approval processes involved, and the strengths and limitations of using routine data to evaluate relevant study outcomes that map to a logic model.&#x0D; Conclusion/ImplicationsThe impact of this evaluation into the effectiveness of FNP in Scotland will establish a robustly matched study cohort, a more strealmined linkage and approval process, and identification of outcomes not only for a short-term follow-up but also for a longer-term follow-up of the teenage mothers and their children.

Bacterial symbionts use a type VI secretion system to eliminate competitors in their natural host

Intraspecific competition describes the negative interaction that occurs when different populations of the same species attempt to fill the same niche. Such competition is predicted to occur among host-associated bacteria but has been challenging to study in natural biological systems. Although many bioluminescent Vibrio fischeri strains exist in seawater, only a few strains are found in the light-organ crypts of an individual wild-caught Euprymna scolopes squid, suggesting a possible role for intraspecific competition during early colonization. Using a culture-based assay to investigate the interactions of different V. fischeri strains, we found "lethal" and "nonlethal" isolates that could kill or not kill the well-studied light-organ isolate ES114, respectively. The killing phenotype of these lethal strains required a type VI secretion system (T6SS) encoded in a 50-kb genomic island. Multiple lethal and nonlethal strains could be cultured from the light organs of individual wild-caught adult squid. Although lethal strains eliminate nonlethal strains in vitro, two lethal strains could coexist in interspersed microcolonies that formed in a T6SS-dependent manner. This coexistence was destabilized upon physical mixing, resulting in one lethal strain consistently eliminating the other. When juvenile squid were coinoculated with lethal and nonlethal strains, they occupied different crypts, yet they were observed to coexist within crypts when T6SS function was disrupted. These findings, using a combination of natural isolates and experimental approaches in vitro and in the animal host, reveal the importance of T6SS in spatially separating strains during the establishment of host colonization in a natural symbiosis.

The effect of introducing a financial incentive to promote application of fluoride varnish in dental practice in Scotland: a natural experiment

BackgroundFinancial incentives are often used to influence professional practice, yet the factors which influence their effectiveness and their behavioural mechanisms are not fully understood. In keeping with clinical guidelines, Childsmile (Scotland’s oral health improvement programme) advocates twice yearly fluoride varnish application (FVA) for children in dental practice. To support implementation Childsmile offered dental practitioners a fee-per-item payment for varnishing 2–5-year-olds’ teeth through a pilot. In October 2011 payment was extended to all dental practitioners. This paper compares FVA pre- and post-roll-out and explores the financial incentive’s behavioural mechanisms.MethodsA natural experimental approach using a longitudinal cohort of dental practitioners (n = 1090) compared FVA pre- (time 1) and post- (time 2) financial incentive. Responses from practitioners who did not work in a Childsmile pilot practice when considering their 2–5-year-old patients (novel incentive group) were compared with all other responses (continuous incentive group). The Theoretical Domains Framework (TDF) was used to measure change in behavioural mechanisms associated with the incentive. Analysis of covariance was used to investigate FVA rates and associated behavioural mechanisms in the two groups.ResultsAt time 2, 709 74%, of eligible responders, were followed up. In general, FVA rates increased over time for both groups; however, the novel incentive group experienced a greater increase (β [95% CI] = 0.82 [0.72 to 0.92]) than the continuous incentive group. Despite this, only 33% of practitioners reported ‘always’ varnishing increased risk 2–5-year-olds’ teeth following introduction of the financial incentive, 19% for standard risk children. Domain scores at time 2 (adjusting for time 1) increased more for the novel incentive group (compared to the continuous incentive group) for five domains: knowledge, social/professional role and identity, beliefs about consequences, social influences and emotion.ConclusionsIn this large, prospective, population-wide study, a financial incentive moderately increased FVA in dental practice. Novel longitudinal use of a validated theoretical framework to understand behavioural mechanisms suggested that financial incentives operate through complex inter-linked belief systems. While financial incentives are useful in narrowing the gap between clinical guidelines and FVA, multiple intervention approaches are required.

Duverger's psychological effect: A natural experiment approach

A large body of work suggests that electoral systems influence the strategic calculus of voters and parties. But electoral rules are endogenous as they originate in the decision making process of voters and parties, making empirical analyses vulnerable to reverse causality and contamination effects. This paper studies a unique case where an electoral system change is exogenously imposed by a supra-national body. I exploit an EU ruling which forced the UK to adopt proportional representation (PR) for European Parliament elections. Using a difference-in-differences design, I estimate the causal impact of the reform on electoral outcomes. I find that the shift to PR leads to more “effective parties” and thus to a more proportional electoral outcome. In line with Duverger's law, the reform causally increased the number of newly entering parties. Existent small parties did not appear to exert more effort. The findings survive several robustness checks.

The effect of area based urban regeneration policies on fuel poverty: Evidence from a natural experiment in Northern Ireland

This paper studies the effect of the most extensive area based regeneration policy in Northern Ireland – Neighbourhood Renewal (NR) – on fuel poverty using a natural experiment approach. NR was launched in 2003 in Northern Ireland as a holistic area-based regeneration policy to improve the lives, prospects and environments of residents living in thirty-six of the nation's most deprived areas over a seven- to ten-year roll-out. Using data from the Northern Ireland Household Panel Survey and from the Understanding Society survey, the effect on fuel poverty during a twelve year period is investigated. Difference-in-difference regression modelling of the impact of NR on fuel poverty provides evidence of a 3.0% reduction in fuel poverty comparing respondents in NR areas with the rest of Northern Ireland and a 4.7% decline relative to a similarly deprived control group. When the effect on heterogeneous characteristics of the sample is explored, the analysis reveals that NR has been particularly effective in relieving fuel poverty among groups with lower qualifications, the retired and those receiving benefits, and has therefore contributed to a reduction in inequalities within the most deprived areas in Northern Ireland.

China’s new rural “separating three property rights” land reform results in grassland degradation: Evidence from Inner Mongolia

China is currently implementing the “separating three property rights” (STPR) reform to consolidate rural land. This reform divides rural land property rights into three components: nontradable ownership, nontradable contractual rights and tradable land use rights. The STPR reform adopts the rental of grassland use rights, a market-oriented approach, as the main arrangement for grassland consolidation. However, this arrangement may undermine the cornerstones of grassland restoration, which are the security of grassland property and payments for ecosystem services (PES) policies. As an alternative to the market-oriented approach, cooperatives are also encouraged to consolidate grassland use rights. We used a natural experiment approach to systematically examine how two different land consolidation arrangements affected key grassland ecosystem services in Inner Mongolia. In rented grasslands, all ecosystem services except provisioning services degenerated severely. Traded grassland use rights were perceived as insecure, which led to predatory land use by tenants. In contrast, cooperative-managed grasslands showed no serious degradation in ecosystem services. However, these cooperatives limited their group size by chief kinship to avoid the free-rider problem; thus, they are unlikely to become a primary channel of grassland consolidation. Because PES policy subsidies are still allocated to grassland contractors rather than to tenants, these policies are irrelevant to the conservation of rented grasslands. Based on our analysis, we suggest several ways to improve this new rural land property reform to avoid a major wave of grassland degradation in China.

Assessing the economic benefits and resilience of complete streets in Orlando, FL: A natural experimental design approach

Abstract Complete Streets are designed to allow for safe access and use for all (e.g., pedestrians, bicyclists, transit commuters, motorists) to improve mobility and accessibility. Retrofitting Complete Street designs acts as an intervention by increasing active transportation activity and providing safety benefits (e.g., reducing motor vehicle involved crashes and injuries); however there is insufficient evidence related to economic benefits of this redesign. This study applied a natural experiment design to: (1) explore the economic benefits on single-family (SF) property value appreciation before-and-after the implementation of the Complete Street during the housing market boom (from 2000 to 2007), and (2) examine the economic resilience of Complete Street designs on maintaining SF property values during the housing market crash (from 2007 to 2011) at Edgewater Dr. in Orlando, FL. Propensity score matching was used to match intervention and control residences with similar building attributes. On average, SF homes exposed to Complete Streets had 8.2% and 4.3% higher home value appreciation and home value resilience than their counterparts in the adjacent non-exposed control area during housing market boom and recession, respectively. Further, on average, SF homes exposed to Complete Streets experienced relatively higher, at 2.7% and 1.6%, home value appreciation and home value resilience than their control counterparts around the nonadjacent auto-oriented control roads during housing market boom and recession, respectively. The implications of this study can inform local planning practice providing evidence that Complete Streets perform better than conventional street designs on maintaining a ‘healthy’ housing market in both economic boom and recession. The economic benefits found can be integrated with research that demonstrates public health and safety benefits of Complete Streets to address the current barriers in implementing Complete Streets and support for policies facilitating the implementation of Complete Streets nationally.

The built environment, travel attitude, and travel behavior: Residential self-selection or residential determination?

In examining the impacts of the built environment on travel behavior, studies focused on residential self-selection mostly assume that people self-select residential built environment based on their travel preferences. However, the residential self-selection hypothesis is challenged for a number of reasons including the arguments that that at least in some societies a large percentage of people do not have the privilege to self-select their residence and the built environment may have a significant influence on a person's travel attitude. To shed some light on this debate, this paper makes use of data from a household activity-diary survey conducted in Beijing, China, in 2011–2012 to examine both the hypothesis of residential self-selection and that of residential environment determination. We adopt the natural experimental approach and divide the sample into two groups based on whether or not the respondents had much freedom in regard to choosing where to live: one with the possibility of self-selection and the other one without this possibility. We found reciprocal influences between residential built environment and travel attitude/preference for the first group and influence of residential built environment on travel preferences for the second group. We argue that the complex relationships between the built environment, travel attitude, and travel behavior are featured by both residential self-selection and residential determination. Failing to acknowledge the effects of the built environment on travel attitude may lead to the overestimation of the influence of residential self-selection on the link between the built environment and travel behavior and underestimation of the influence of the built environment on travel behavior.

Association between NICE guidance on biologic therapies with rates of hip and knee replacement among rheumatoid arthritis patients in England and Wales: An interrupted time-series analysis.

To estimate the impact of NICE approval of tumor necrosis factor inhibitor (TNFi) therapies on the incidence of total hip replacement (THR) and total knee replacement (TKR) among rheumatoid arthritis (RA) patients in England and Wales. Primary care data [Clinical Practice Research Datalink (CPRD)] for the study period (1995-2014) were used to identify incident adult RA patients. The age and sex-standardised 5-year incidence of THR and TKR was calculated separately for RA patients diagnosed in each six-months between 1995-2009. We took a natural experimental approach, using segmented linear regression to estimate changes in level and trend following the publication of NICE TA 36 in March 2002, incorporating a 1-year lag. Regression coefficients were used to calculate average change in rates, adjusted for prior level and trend. We identified 17,505 incident RA patients of whom 465 and 650 underwent THR and TKR surgery, respectively. The modeled average incidence of THR and TKR over the biologic-era was 6.57/1000 person years (PYs) and 8.51/1000 PYs, respectively, with projected (had pre-NICE TA 36 level and trend continued uninterrupted) figures of 5.63/1000 PYs and 12.92 PYs, respectively. NICE guidance was associated with a significant average decrease in TKR incidence of -4.41/1000 PYs (95% C.I. -6.88 to -1.94), equating to a relative 34% reduction. Overall, no effect was seen on THR rates. Among incident RA patients in England and Wales, NICE guidance on TNFi therapies for RA management was temporally associated with reduced rates of TKR but not THR.