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Dive into the research topics where Theo Postma is active.

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Featured researches published by Theo Postma.


Journal of Neurology, Neurosurgery, and Psychiatry | 1997

Effect of intrathecal baclofen delivered by an implanted programmable pump on health related quality of life in patients with severe spasticity

Berrie Middel; Hanna Kuipers-Upmeijer; Jelte Bouma; Michiel J. Staal; Dettie Oenema; Theo Postma; Sijmon Terpstra; Roy E. Stewart

OBJECTIVES To compare clinical effectiveness and health related quality of life in patients with severe spasticity who received intrathecal baclofen or a placebo. METHODS In a double blind, randomised, multicentre trial 22 patients were followed up during 13 weeks and subsequently included in a 52 week observational longitudinal study. Patients were those with chronic, disabling spasticity who did not respond to maximum doses of oral baclofen, dantrolene, and tizanidine. After implantation of a programmable pump patients were randomly assigned to placebo or baclofen infusion for 13 weeks. After 13 weeks all patients received baclofen. Clinical efficacy was assessed by the Ashworth scale, spasm score, and self reported pain, and health related quality of life by the sickness impact profile (SIP) and the Hopkins symptom checklist (HSCL). RESULTS At three months the scores of the placebo and baclofen group differed slightly for the spasm score (effect size=0.20) and substantially for the Ashworth scale (effect size=1.40) and pain score (effect size=0.94); health related quality of life showed no significant differences. Three months after implantation the baclofen group showed a significant, substantial improvement on the SIP “physical health”, “mental health”, “mobility”, and “sleep and rest” subscales and on the HSCL mental health scale; patients receiving placebo showed no change. After one year of baclofen treatment significant (P<0.05) improvement was found on the SIP dimensions “mobility” and “body care and movement” with moderate effect sizes. Improvement on the SIP subscale “physical health” (P<0.05; effect size 0.86), the SIP overall score (without “ambulation”), and the “physical health” and overall scale of the HSCL was also significant, with effect sizes >0.80. Changes in health related behaviour were noted for “sleep and rest” and “recreation and pastimes” (P<0.01, P<0.05; effect size 0.95 and 0.63, respectively). Psychosocial behaviour showed no improvement. CONCLUSIONS Intrathecal baclofen delivered by an implanted, programmable pump resulted in improved self reported quality of life as assessed by the SIP, and HSCL physical health dimensions also suggest improvement.


Corporate Governance: An International Review | 2007

Corporate governance in the Netherlands : An overview of the application of the Tabaksblat Code in 2004

Dirk Akkermans; Hans van Ees; Niels Hermes; Reggy Hooghiemstra; Gerwin van der Laan; Theo Postma; Arjen van Witteloostuijn

This article examines the overall acceptance of the best practice provisions contained in the Dutch corporate governance code and identifies those that receive comparably less agreement among 150 Dutch listed companies in 2004. The findings indicate a high level of compliance with the Code. Moreover, the extent of compliance is positively associated with company size. Provisions related to the remuneration of board members, independence of supervisory board members, and requirements with respect to internal control systems stand out when it comes to non-compliance. In addition, the nature and content of the explanations provided for non-compliance are remarkably similar across companies, which may indicate symbolic compliance with the Codes best practice provisions.


International Journal of Managerial Finance | 2006

Corporate governance codes in the European Union: Are they driven by external or domestic forces?

Niels Hermes; Theo Postma; Orestis Zivkov

Purpose – The paper seeks to analyze to what extent the contents of corporate governance codes of countries in the European Union are driven by external (internationally accepted corporate governance best practices) or domestic (institutions, culture, etc.) forces. Design/methodology/approach – The paper compares the contents of codes with the priorities set by the European Commission with respect to modernising company law and enhancing corporate governance in the European Union. Findings – The analysis shows that the majority of the codes of the European Union countries are not in full accordance with the priorities of the European Commission. This may reflect that codes are driven by both external and domestic forces. Whether there is a difference between Western European and Central and Eastern European countries in this respect is also investigated, but no difference, at least at the aggregate level of the codes of both groups of countries has been found. Research limitations/implications – The analysis excludes five (prospective) European Union members. The analysis does not provide a comprehensive overview of domestic determinants of why codes of individual countries diverge from the European Union communication. Future research should systematically explore whether and to what extent domestic forces are indeed determining the contents of codes and, if so, which country-specific forces have an impact on establishing code contents. Originality/value – This paper is the first comprehensive attempt to analyse the contents of corporate governance codes. Such an analysis is important to understand the underlying forces that shape the diffusion of codes and their contents.


PharmacoEconomics | 1999

Cost Analysis of the Treatment of Severe Spinal Spasticity With a Continuous Intrathecal Baclofen Infusion System

Theo Postma; Dettie Oenema; Symon Terpstra; Jelte Bouma; Hannah Kuipers-Upmeijer; Michiel J. Staal; Berry J. Middel

AbstractObjective: The purpose of our study was to analyse and evaluate the costs of continuous intrathecal baclofen administration as a modality in the treatment of severe spasticity in the Netherlands. Design: A cost analysis was conducted as part of a prospective, multicentre, multidisciplinary, randomised and placebo-controlled clinical trial. The study covered the period from December 1991 to September 1995. The data on medical consumption and costs were collected over a 3-year period from different sources: administrative databases of health insurance companies, hospital registries and a patient survey. These data were structured by means of a flowchart analysis of the medical decision-making by specialists and general practitioners (GPs). They included data on in- and outpatient care, home care and care in nursing homes.The cost analysis was conducted using data from 18 patients included in the trial and from 15 so-called ‘match’ patients. The latter group are patients with comparable diseases leading to spasticity and living in comparable circumstances. Next to absolute costs (direct and indirect) of care and treatment for the 2 groups of patients, cost differences between the 2 groups were considered (differential cost analysis). Setting: Per patient cost data, collected prospectively for 2 years during the phase of clinical evaluation, and retrospectively 1 year before implantation. The data were collected on patients from in- and outpatient care, home care and care in nursing home settings. Patients and participants: The trial patients (8 men) had a mean age of 46 years; 11 patients had multiple sclerosis and 7 patients had spinal cord injuries. The match patients (7 men) had a mean age of 48 years; 9 patients had multiple sclerosis and 6 patients had spinal cord injuries. Interventions: Trial patients were treated with a subcutaneously implanted programmable continuous infusion pump (SynchroMed, Medtronic), filled with baclofen (a muscle relaxant) to treat patients with chronic disabling spasticity who did not respond to a maximum dose of oral baclofen, dantrolene and tizanidine. Main outcome measures and results: An analysis of hospital stay between both groups showed a significant difference during the implantation year. The average number of hospital days per patient in that year in the treated group was 31.5 days and in the match group was 18.7 days. Significant cost differences between both groups in the year that started with pump implantation and the following year can be attributed mostly to the costs of implantation of the pump and related hospitalisation days. The total costs of patient selection, testing, implanting the pump and follow-up amounted to


Entrepreneurship Theory and Practice | 2007

The influence of the venture capitalist's governance activities on the entrepreneurial firm's control systems and performance

F.H. Wijbenga; Theo Postma; Rebecca Stratling

US28 473 for the first year. Savings must be taken into consideration as well. The savings of direct costs were due to withdrawal of oral medication (estimated annual total of between


Journal for East European Management Studies | 2007

Corporate governance codes and their contents - An analysis of Eastern European codes

Niels Hermes; Theo Postma; Orestis Zivkov

US1950 and


Technology Analysis & Strategic Management | 2010

Governance factors enabling knowledge transfer in interorganisational development projects

Petra M. Bosch-Sijtsema; Theo Postma

US2800 per patient). Indirect savings on employment and nursing home costs, amounted annually to


European Journal of Health Economics | 2006

The future of imaging techniques for cancer patients in The Netherlands

Theo Postma; Janneke C. Alers; Sijmon Terpstra; Arjan Zuurbier

US1047 and


European Management Journal | 1999

Organizational diagnosis in practice: a cross-classification analysis using the DEL-technique

Theo Postma; R.A.W. Kok

US5814, respectively.Scenarios make it possible to consider policy consequences. The case of ‘extending’ the indications for this treatment to a larger population has been calculated and visualised. Conclusions: The costs of the therapy (continuous intrathecal infusion of baclofen) can be attributed mostly to implantation of the pump and related hospitalisation days. Savings originated from withdrawal of oral medication, job preservation and avoidance or delay of admission to a nursing home.


International Journal of Business Governance and Ethics | 2015

Supervisory boards in high growth SMEs and mandated board members: two dilemmas

Maryse Brand; Theo Postma

Venture capitalists (VCs) contribute to entrepreneurial firms by engaging in governance activities, such as providing services and monitoring the entrepreneurial firms operations and performance. This study examines the role and influence of the VCs governance activities on 93 Dutch entrepreneurial firms. Results suggest that while the VCs governance activities may help to stimulate the use of the entrepreneurial firms control systems, they also moderate the relationship between the entrepreneurial firms use of control systems and its financial performance. It appears in particular that cost control systems contribute positively to the entrepreneurial firms financial performance when the VC provides service activities. However, the use of cost control systems tends to be negatively related to the entrepreneurial firms financial performance when the VC is highly focused on monitoring.

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Niels Hermes

University of Groningen

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Hans van Ees

University of Groningen

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R.A.W. Kok

Radboud University Nijmegen

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Petra M. Bosch-Sijtsema

Chalmers University of Technology

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