Ana Paula Martins
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Ana Paula Martins has a total of 18 co-authors. Here are the top co-authors by number of shared publications:
- Helena Ferreira
Centro de Matemática e Aplicações (CMA-UBI) Universidade da Beira Interior Avenida Marquês d'Avila e Bolama 6200-001 Covilhã Portugal
19 shared publications - Luísa Pereira
University of Beira Interior
12 shared publications - Clara Viseu
Polytechnic University of Coimbra, Rua da Misericórdia, Lagar dos Cortiços, S. Martinho do Bispo, 3045-093 Coimbra, Portugal
4 shared publications - João Renato Sebastião
Polytechnic Institute of Castelo Branco, Polytechnic University, 6000-084 Castelo Branco, Portugal
4 shared publications - Cecília Fonseca
Polytechnic of Guarda, 6300-559 Guarda, Portugal, Portugal
3 shared publications - Rosa Marina Afonso
University of Beira Interior
3 shared publications
Latest Publications
- Open Access
- 29 July 2025
- Published by Taylor & Francis in Death Studies
- Vol. 50 (9) , 1-10
Profiles of death attitudes of professionals who support community living older adults
Death is a frequent event for those professionals who work with older adults in day care centers (DCC) and home care services (HCS). This study aimed to profile the attitudes toward death of professionals who support community living older adults. This quantitative cross-sectional observational study used an online survey comprising a sociodemographic and professional questionnaire, the Death Attitude Profile-Revised (DAP-R) and the Satisfaction with Life scale (SWL). A convenience sample of 201 participants revealed, through cluster analysis three profiles of attitudes toward death: Neutral Acceptance (48.3%), Negative Attitudes (30.3%), and Mixed Attitudes (21.4%). Socio-demographically, only formal education was significantly associated with attitude profiles. Professionals working at DCC have a significantly higher prevalence of neutral attitudes, compared to HCS professionals. It is crucial to invest in the training and professional development of those supporting older adults in the community, particularly addressing negative and mixed attitudes toward death.
- 29 July 2025
- Published by Taylor & Francis in Death Studies
- Vol. 50 (9) , 1-10
Open AccessProfiles of death attitudes of professionals who support community living older adults
Death is a frequent event for those professionals who work with older adults in day care centers (DCC) and home care services (HCS). This study aimed to profile the attitudes toward death of professionals who support community living older adults. This quantitative cross-sectional observational study used an online survey comprising a sociodemographic and professional questionnaire, the Death Attitude Profile-Revised (DAP-R) and the Satisfaction with Life scale (SWL). A convenience sample of 201 participants revealed, through cluster analysis three profiles of attitudes toward death: Neutral Acceptance (48.3%), Negative Attitudes (30.3%), and Mixed Attitudes (21.4%). Socio-demographically, only formal education was significantly associated with attitude profiles. Professionals working at DCC have a significantly higher prevalence of neutral attitudes, compared to HCS professionals. It is crucial to invest in the training and professional development of those supporting older adults in the community, particularly addressing negative and mixed attitudes toward death.
- Open Access
- 21 July 2025
- Published by JMIR Publications Inc. in JMIR Preprints
Perceived Vulnerability to Disease Scale: Factorial structure, reliability and validity in times of Portugal’s COVID-19 pandemic lockdown (Preprint)
UNSTRUCTURED Objective: The present study examines the factor structure of a Portuguese version (Marques, 2016) of the perceived vulnerability to disease scale (PVD; Duncan, Schaller & Park, 2009), designed to assess individual differences in chronic concerns about transmission of infectious diseases. Method: Data from a Portuguese convenience sample (n=1203), collected during the first Covid-19 pandemic lockdown. Results: The scale revealed, through an exploratory factor analysis (EFA) and a confirmatory factor analysis (CFA), a slight superiority of a three-factor model over the existing two-factor models of the 15-item original PVD and of the 10-item PVD established with another Portuguese sample (Ferreira et al., 2022). Conclusions: This higher level of differentiation in terms of a perceived resistance to infectious diseases could be explained by the pandemic context which may have differentiated the responses regarding the perception of Resistance. On the other hand, this new factor increases the comprehensive and evaluative dimension and implications of the construct assessed by PVD.
- 21 July 2025
- Published by JMIR Publications Inc. in JMIR Preprints
Open AccessPerceived Vulnerability to Disease Scale: Factorial structure, reliability and validity in times of Portugal’s COVID-19 pandemic lockdown (Preprint)
UNSTRUCTURED Objective: The present study examines the factor structure of a Portuguese version (Marques, 2016) of the perceived vulnerability to disease scale (PVD; Duncan, Schaller & Park, 2009), designed to assess individual differences in chronic concerns about transmission of infectious diseases. Method: Data from a Portuguese convenience sample (n=1203), collected during the first Covid-19 pandemic lockdown. Results: The scale revealed, through an exploratory factor analysis (EFA) and a confirmatory factor analysis (CFA), a slight superiority of a three-factor model over the existing two-factor models of the 15-item original PVD and of the 10-item PVD established with another Portuguese sample (Ferreira et al., 2022). Conclusions: This higher level of differentiation in terms of a perceived resistance to infectious diseases could be explained by the pandemic context which may have differentiated the responses regarding the perception of Resistance. On the other hand, this new factor increases the comprehensive and evaluative dimension and implications of the construct assessed by PVD.
- Open Access
- 1 January 2023
- Published by FapUNIFESP (SciELO) in Revista do Colégio Brasileiro de Cirurgiões
- Vol. 50, e20233537
Fatores de risco na persistência ou recidiva da Lesão escamosa intraepitelial de alto grau (LIEAG)
RESUMO Objetivos: avaliar se o status das margens, idade, tamanho da lesão colposcópica, tipo de cirurgia e expressão dos marcadores p16/Ki-67 são fatores de risco na persistência ou recidiva da LIEAG. Métodos: um estudo de corte transversal, observacional com coleta de dados retrospectivos de pacientes submetidas a conização a frio (CF) ou exérese da zona de transformação por cirurgia de alta frequência EZT por NIC2/3. Foram analisados os seguintes fatores em relação a persistência ou recidiva: comprometimento das margens, idade, tamanho da lesão, tipo de cirurgia e coexpressão dos imunomarcadores p16 e Ki-67. Resultados: 271 mulheres tratadas com CF (71) e EZT (200), onde 95 apresentavam NIC 2 e 173 NIC 3, 183 apresentaram margens cirúrgicas livres, 76 comprometidas e 12 prejudicadas por artefatos ou fragmentação. Das 76 pacientes com margens comprometidas, 55 foram endocervical, 11 ectocervical e 10 ambas as margens. Das 264 pacientes que tiveram seguimento, 38 persistiram ou recidivaram a doença. A regressão logística múltipla indicou ser a margem endocervical comprometida o único fator independente de risco de persistência/recorrência da NIC (p<0,001). Não houve associação significativa entre a idade, o tamanho da lesão colposcópica, o tipo de cirurgia e a expressão dos imunomarcadores p16/Ki-67 e a persistência ou recorrência da doença. Conclusão: entre os fatores estudados associados com persistência ou recorrência, somente a margem endocervical comprometida provou ser significativamente um fator risco para persistência ou recorrência da lesão.
- 1 January 2023
- Published by FapUNIFESP (SciELO) in Revista do Colégio Brasileiro de Cirurgiões
- Vol. 50, e20233537
Open AccessFatores de risco na persistência ou recidiva da Lesão escamosa intraepitelial de alto grau (LIEAG)
RESUMO Objetivos: avaliar se o status das margens, idade, tamanho da lesão colposcópica, tipo de cirurgia e expressão dos marcadores p16/Ki-67 são fatores de risco na persistência ou recidiva da LIEAG. Métodos: um estudo de corte transversal, observacional com coleta de dados retrospectivos de pacientes submetidas a conização a frio (CF) ou exérese da zona de transformação por cirurgia de alta frequência EZT por NIC2/3. Foram analisados os seguintes fatores em relação a persistência ou recidiva: comprometimento das margens, idade, tamanho da lesão, tipo de cirurgia e coexpressão dos imunomarcadores p16 e Ki-67. Resultados: 271 mulheres tratadas com CF (71) e EZT (200), onde 95 apresentavam NIC 2 e 173 NIC 3, 183 apresentaram margens cirúrgicas livres, 76 comprometidas e 12 prejudicadas por artefatos ou fragmentação. Das 76 pacientes com margens comprometidas, 55 foram endocervical, 11 ectocervical e 10 ambas as margens. Das 264 pacientes que tiveram seguimento, 38 persistiram ou recidivaram a doença. A regressão logística múltipla indicou ser a margem endocervical comprometida o único fator independente de risco de persistência/recorrência da NIC (p<0,001). Não houve associação significativa entre a idade, o tamanho da lesão colposcópica, o tipo de cirurgia e a expressão dos imunomarcadores p16/Ki-67 e a persistência ou recorrência da doença. Conclusão: entre os fatores estudados associados com persistência ou recorrência, somente a margem endocervical comprometida provou ser significativamente um fator risco para persistência ou recorrência da lesão.
- Open Access
- 1 January 2023
- Published by FapUNIFESP (SciELO) in Revista do Colégio Brasileiro de Cirurgiões
- Vol. 50, e20233537
Risk Factors for Persistence or Recurrence of High-Grade Cervical Squamous Intraepithelial Lesions
to evaluate whether the colposcopic lesion size , age, kind of surgery, the status of the surgical margins and the expression of the p16 and Ki-67 immunomarkers are risk factors for persistence or recurrence of the lesion.
- 1 January 2023
- Published by FapUNIFESP (SciELO) in Revista do Colégio Brasileiro de Cirurgiões
- Vol. 50, e20233537
Open AccessRisk Factors for Persistence or Recurrence of High-Grade Cervical Squamous Intraepithelial Lesions
to evaluate whether the colposcopic lesion size , age, kind of surgery, the status of the surgical margins and the expression of the p16 and Ki-67 immunomarkers are risk factors for persistence or recurrence of the lesion.
- 25 February 2021
- Published by Taylor & Francis in Death Studies
- Vol. 46 (9) , 2093-2099
The fear of the COVID-19 Scale: validation in the Portuguese general population
The coronavirus disease (COVID-19) pandemic is having a profound effect on mental health and it is therefore fundamental to evaluate individual psychological responses to COVID-19. The 7-item Fear of COVID-19 Scale (FCV-19S) assesses different aspects of the fear of coronavirus and has been applied worldwide. This study aimed to translate and validate the FCV-19S in the Portuguese population. The scale was administered to a convenience sample of 1203 Portuguese adults. Exploratory factor analysis was carried out on the initial model proposed by the authors of the FCV-19S. Further analysis revealed that the Portuguese version has good psychometric properties.
- 25 February 2021
- Published by Taylor & Francis in Death Studies
- Vol. 46 (9) , 2093-2099
The fear of the COVID-19 Scale: validation in the Portuguese general population
The coronavirus disease (COVID-19) pandemic is having a profound effect on mental health and it is therefore fundamental to evaluate individual psychological responses to COVID-19. The 7-item Fear of COVID-19 Scale (FCV-19S) assesses different aspects of the fear of coronavirus and has been applied worldwide. This study aimed to translate and validate the FCV-19S in the Portuguese population. The scale was administered to a convenience sample of 1203 Portuguese adults. Exploratory factor analysis was carried out on the initial model proposed by the authors of the FCV-19S. Further analysis revealed that the Portuguese version has good psychometric properties.
- 6 February 2021
- Published by Springer Nature in Statistical Papers
- Vol. 62 (6) , 2991-3013
Extremal behaviour of a periodically controlled sequence with imputed values
- 6 February 2021
- Published by Springer Nature in Statistical Papers
- Vol. 62 (6) , 2991-3013
Extremal behaviour of a periodically controlled sequence with imputed values
- Open Access
Extremal behaviour of a periodically controlled sequence with imputed values
Extreme events are a major concern in statistical modeling. Ran\-dom missing data can constitute a problem when modeling such rare events. Imputation is crucial in these situations and therefore models that describe different imputation functions enhance possible applications and enlarge the few known families of models which cover these situations. In this paper we consider a family of models $\{Y_n\},$ $n\geq 1,$ which can be associated to automatic systems which have a periodic control, in the sense that it is guaranteed that at instants multiple of $T,$ $T\geq 2,$ no value is lost. Random missing values are here replaced by the biggest of the previous observations up to the one surely registered. We prove that when the underlying sequence is stationary, $\{Y_n\}$ is $T-$periodic and if it also verifies some local dependence conditions then $\{Y_n\}$ verifies one of the well known $D^{(s)}_T(u_n),$ $s\geq 1,$ dependence conditions for $T-$periodic sequences. We also obtain the extremal index of $\{Y_n\}$ and relate it to the extremal index of the underlying sequence. A consistent estimator for the parameter that "controls" the missing values is here proposed and its finite sample properties are analysed. The obtained results are illustrated with Markovian sequences of recognized interest in applications.Open AccessExtremal behaviour of a periodically controlled sequence with imputed values
Extreme events are a major concern in statistical modeling. Ran\-dom missing data can constitute a problem when modeling such rare events. Imputation is crucial in these situations and therefore models that describe different imputation functions enhance possible applications and enlarge the few known families of models which cover these situations. In this paper we consider a family of models $\{Y_n\},$ $n\geq 1,$ which can be associated to automatic systems which have a periodic control, in the sense that it is guaranteed that at instants multiple of $T,$ $T\geq 2,$ no value is lost. Random missing values are here replaced by the biggest of the previous observations up to the one surely registered. We prove that when the underlying sequence is stationary, $\{Y_n\}$ is $T-$periodic and if it also verifies some local dependence conditions then $\{Y_n\}$ verifies one of the well known $D^{(s)}_T(u_n),$ $s\geq 1,$ dependence conditions for $T-$periodic sequences. We also obtain the extremal index of $\{Y_n\}$ and relate it to the extremal index of the underlying sequence. A consistent estimator for the parameter that "controls" the missing values is here proposed and its finite sample properties are analysed. The obtained results are illustrated with Markovian sequences of recognized interest in applications. - Open Access
- 30 March 2017
- Published by Springer Nature in Extremes
- Vol. 20 (4) , 807-838
Clustering of high values in random fields
- 30 March 2017
- Published by Springer Nature in Extremes
- Vol. 20 (4) , 807-838
Open AccessClustering of high values in random fields
- Open Access
- 3 February 2017
- Published by Springer Nature in Statistical Papers
- Vol. 60 (4) , 1317-1347
Methods for estimating the upcrossings index: improvements and comparison
- 3 February 2017
- Published by Springer Nature in Statistical Papers
- Vol. 60 (4) , 1317-1347
Open AccessMethods for estimating the upcrossings index: improvements and comparison
- Open Access
Clustering of high values in random fields
The asymptotic results that underlie applications of extreme random fields often assume that the variables are located on a regular discrete grid, identified with $\mathbb{Z}^2$, and that they satisfy stationarity and isotropy conditions. Here we extend the existing theory, concerning the asymptotic behavior of the maximum and the extremal index, to non-stationary and anisotropic random fields, defined over discrete subsets of $\mathbb{R}^2$. We show that, under a suitable coordinatewise long range dependence condition, the maximum may be regarded as the maximum of an approximately independent sequence of submaxima, although there may be high local dependence leading to clustering of high values. Under restrictions on the local path behavior of high values, criteria are given for the existence and value of the spatial extremal index which plays a key role in determining the cluster sizes and quantifying the strength of dependence between exceedances of high levelsThe general theory is applied to the class of max-stable random fields, for which the extremal index is obtained as a function of well-known tail dependence measures found in the literature, leading to a simple estimation method for this parameter. The results are illustrated with non-stationary Gaussian and 1-dependent random fields. For the latter, a simulation and estimation study is performed.Open AccessClustering of high values in random fields
The asymptotic results that underlie applications of extreme random fields often assume that the variables are located on a regular discrete grid, identified with $\mathbb{Z}^2$, and that they satisfy stationarity and isotropy conditions. Here we extend the existing theory, concerning the asymptotic behavior of the maximum and the extremal index, to non-stationary and anisotropic random fields, defined over discrete subsets of $\mathbb{R}^2$. We show that, under a suitable coordinatewise long range dependence condition, the maximum may be regarded as the maximum of an approximately independent sequence of submaxima, although there may be high local dependence leading to clustering of high values. Under restrictions on the local path behavior of high values, criteria are given for the existence and value of the spatial extremal index which plays a key role in determining the cluster sizes and quantifying the strength of dependence between exceedances of high levelsThe general theory is applied to the class of max-stable random fields, for which the extremal index is obtained as a function of well-known tail dependence measures found in the literature, leading to a simple estimation method for this parameter. The results are illustrated with non-stationary Gaussian and 1-dependent random fields. For the latter, a simulation and estimation study is performed.