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Item 9 of the Patient Health Questionnaire-9 (PHQ-9) queries about thoughts of death and self-harm, but not suicidality. Although it is sometimes used to assess suicide risk, most positive responses are not associated with suicidality. The PHQ-8, which omits Item 9, is thus increasingly used in research. We assessed equivalency of total score correlations and the diagnostic accuracy to detect major depression of the PHQ-8 and PHQ-9.
We conducted an individual patient data meta-analysis. We fit bivariate random-effects models to assess diagnostic accuracy.
16 742 participants (2097 major depression cases) from 54 studies were included. The correlation between PHQ-8 and PHQ-9 scores was 0.996 (95% confidence interval 0.996 to 0.996). The standard cutoff score of 10 for the PHQ-9 maximized sensitivity + specificity for the PHQ-8 among studies that used a semi-structured diagnostic interview reference standard (N = 27). At cutoff 10, the PHQ-8 was less sensitive by 0.02 (−0.06 to 0.00) and more specific by 0.01 (0.00 to 0.01) among those studies (N = 27), with similar results for studies that used other types of interviews (N = 27). For all 54 primary studies combined, across all cutoffs, the PHQ-8 was less sensitive than the PHQ-9 by 0.00 to 0.05 (0.03 at cutoff 10), and specificity was within 0.01 for all cutoffs (0.00 to 0.01).
PHQ-8 and PHQ-9 total scores were similar. Sensitivity may be minimally reduced with the PHQ-8, but specificity is similar.
Different diagnostic interviews are used as reference standards for major depression classification in research. Semi-structured interviews involve clinical judgement, whereas fully structured interviews are completely scripted. The Mini International Neuropsychiatric Interview (MINI), a brief fully structured interview, is also sometimes used. It is not known whether interview method is associated with probability of major depression classification.
To evaluate the association between interview method and odds of major depression classification, controlling for depressive symptom scores and participant characteristics.
Data collected for an individual participant data meta-analysis of Patient Health Questionnaire-9 (PHQ-9) diagnostic accuracy were analysed and binomial generalised linear mixed models were fit.
A total of 17 158 participants (2287 with major depression) from 57 primary studies were analysed. Among fully structured interviews, odds of major depression were higher for the MINI compared with the Composite International Diagnostic Interview (CIDI) (odds ratio (OR) = 2.10; 95% CI = 1.15–3.87). Compared with semi-structured interviews, fully structured interviews (MINI excluded) were non-significantly more likely to classify participants with low-level depressive symptoms (PHQ-9 scores ≤6) as having major depression (OR = 3.13; 95% CI = 0.98–10.00), similarly likely for moderate-level symptoms (PHQ-9 scores 7–15) (OR = 0.96; 95% CI = 0.56–1.66) and significantly less likely for high-level symptoms (PHQ-9 scores ≥16) (OR = 0.50; 95% CI = 0.26–0.97).
The MINI may identify more people as depressed than the CIDI, and semi-structured and fully structured interviews may not be interchangeable methods, but these results should be replicated.
Declaration of interest
Drs Jetté and Patten declare that they received a grant, outside the submitted work, from the Hotchkiss Brain Institute, which was jointly funded by the Institute and Pfizer. Pfizer was the original sponsor of the development of the PHQ-9, which is now in the public domain. Dr Chan is a steering committee member or consultant of Astra Zeneca, Bayer, Lilly, MSD and Pfizer. She has received sponsorships and honorarium for giving lectures and providing consultancy and her affiliated institution has received research grants from these companies. Dr Hegerl declares that within the past 3 years, he was an advisory board member for Lundbeck, Servier and Otsuka Pharma; a consultant for Bayer Pharma; and a speaker for Medice Arzneimittel, Novartis, and Roche Pharma, all outside the submitted work. Dr Inagaki declares that he has received grants from Novartis Pharma, lecture fees from Pfizer, Mochida, Shionogi, Sumitomo Dainippon Pharma, Daiichi-Sankyo, Meiji Seika and Takeda, and royalties from Nippon Hyoron Sha, Nanzando, Seiwa Shoten, Igaku-shoin and Technomics, all outside of the submitted work. Dr Yamada reports personal fees from Meiji Seika Pharma Co., Ltd., MSD K.K., Asahi Kasei Pharma Corporation, Seishin Shobo, Seiwa Shoten Co., Ltd., Igaku-shoin Ltd., Chugai Igakusha and Sentan Igakusha, all outside the submitted work. All other authors declare no competing interests. No funder had any role in the design and conduct of the study; collection, management, analysis and interpretation of the data; preparation, review or approval of the manuscript; and decision to submit the manuscript for publication.
Fluvial geomorphology and stratigraphy often reflect past environmental and climate conditions. This study examines the response of Bull Creek, a small ephemeral creek in the Oklahoma panhandle, to environmental conditions through the late Pleistocene and Holocene. Fluvial terraces were mapped and their stratigraphy and sedimentology documented throughout the course of the main valley. Based on their elevations, terraces were broadly grouped into a late-Pleistocene fill terrace (T3) and two Holocene fill-cut terrace sets (T2 and T1). Terrace systems are marked by similar stratigraphies recording the general environmental conditions of the time. Sedimentary sequences preserved in terrace fills record the transition from a perennial fluvial system during the late glacial period and the Younger Dryas to a semiarid environment dominated by loess accumulation and punctuated by flood events during the middle to late Holocene. The highest rates of aeolian accumulation within the valley occurred during the early to middle Holocene. Our data provide significant new information regarding the late-Pleistocene and Holocene environmental history for this region, located between the well-studied Southern and Central High Plains of North America.
As an experiment, special holiday programs for primary school children were offered by the Carter Observatory during two different school holidays in 1995. One program focussed on Mars and the other on the Sun. This paper describes the two programs, expands on their strengths and weaknesses from different viewpoints, and (despite their overwhelming popularity) outlines the reasons why the Observatory has decided not to offer further holiday programs of this type in the foreseeable future.
It has become popular in recent years to talk about 'identity' as an aspect of engagement with technology - in virtual environments, in games, in social media and in our increasingly digital world. But what do we mean by identity and how do our theories and assumptions about identity affect the kinds of questions we ask about its relationship to technology and learning? Constructing the Self in a Digital World takes up this question explicitly, bringing together authors working from different models of identity but all examining the role of technology in the learning and lives of children and youth.
The formal commissioning of the IRWG occurred at the 1991 Buenos Aires General Assembly, following a Joint Commission meeting at the IAU GA in Baltimore in 1988 that identified the problems with ground-based infrared photometry. The meeting justification, papers, and conclusions, can be found in Milone (1989). In summary, the challenges involved how to explain the failure to achieve the milli-magnitude precision expected of infrared photometry and an apparent 3% limit on system transformability. The proposed solution was to redefine the broadband Johnson system, the passbands of which had proven so unsatisfactory that over time effectively different systems proliferated, although bearing the same “JHKLMNQ” designations; the new system needed to be better positioned and centered in the spectral windows of the Earth's atmosphere, and the variable water vapour content of the atmosphere needed to be measured in real time to better correct for atmospheric extinction.
The influence of porosity and densification on optical properties of films on sapphire substrates that were prepared from water colloidal suspensions of small (∼5nm) particles of ceria was investigated. The colloidal ceria films have initially very porous structure (porosity about 50%) and densification starts at about 600°oC accompanied by grain growth. The concurrence of these two processes makes it difficultto interpret the results of the optical spectrophotometry, but the combination of transmittance and reflectance measurements provides enough data to separate these two influences and to calculate the porosity, particlesize and energy band gap separately. XRD, SEM, ellipsometry and mechanical profilometry were used to confirm the results obtained from the specrophotometric measurements. All these methods gave results, which are in good agreement: the change in the porosity from 50% to 15% and the particle size increased from 5 to 65nm in the temperature region from 400 to 1000°oC. An important result of the investigation is the fact that the main optical properties of the coating such as refractive index and band gap energy depend only on the porosity, but not on the grain size. The grain size influences the scattering properties of the coating, which allows the grain size to be estimated from optical measurements.
Grain boundaries in YBa2Cu3O7-δ thin films deposited on (001)-MgO by pulsed laser ablation have been characterized using selected area diffraction. In addition to twin boundaries, the presence of both low-angle and high-angle grain boundaries were characteristic of the film's microstructure. The presence of certain grain boundaries may be responsible for the weak-link Josephson behavior observed in small constrictions formed in superconducting films on MgO.
Using an accurate tight-binding method, we examine the structure and dynamics at a C(lll) step. We find the H vibration frequencies at a step are distinguishable from the flat surface. Removal of H from the surface creates an unstable bulk terminated diamond structure which relaxes to a graphitic layer and pulls away from the bulk. The explanation for these results can be given in terms of the relationship of the band structure to the relaxed geometries. The addition of H stabilizes this surface and reverts it back to sp3 bonding. The addition of CH3 near a step is also discussed. These results are important towards the understanding of possible diamond growth mechanisms that occur at a step.