Involvement and Autonomy of Minors in Medical Settings: Perceptions of Children Undergoing Surgery and Parents.

Informed consent presupposes competence and represents a formal decision by an informed person who has the legal capacity to accept medical action or participate in research. Our aim was to analyze the perceptions of minors and their parents about the age at which they consider that a minor is competent for making health decisions. A descriptive observational study was carried out in 302 minors between 12 and 17 years of age undergoing elective surgery, and 302 parents (range 30 to 62 years). Two semistructured questionnaires were designed, one for the minors and the other, for the parents. A total of 20.1% of minors and 31.1% of parents believe that patients should not make decisions related to their health until they are 18 years old. A total of 74.9% of the minors surveyed consider that from 16 years of age, the minor is empowered to make decisions. In parents, this percentage is 60%. In the pediatric setting, each case and situation must be examined individually to determine if the minor meets the condition of maturity to decide. The ideal is to promote the minor's participation in decision-making, giving them the opportunity to participate in the process in a manner appropriate to their capacity.

Combining Oxidative Stress Markers and Expression of Surfactant Protein A in Lungs in the Diagnosis of Seawater Drowning.

BACKGROUND AND OBJECTIVES: The diagnosis of seawater drowning (SWD) remains one of the most complex and contentious. It is one of the leading causes of unintentional death around the world. In most cases, the forensic pathologist must reach an accurate diagnosis from the autopsy findings and a series of complementary tests such as histopathological, biological, and chemical studies. Despite the lung being the most affected organ in death by submersion, there are few studies on this type of death's impact on this organ. The aim was to investigate human lung cadavers of forensic cases due to different causes of death, the concentration of the oxidative stress markers malondialdehyde (MDA) and γ-glutamyl-l-cysteinyl glycine (GSH), and the relationship with the expression of surfactant protein A (SP-A) to try to discriminate SWD from other types of causes of death. MATERIALS AND METHODS: A total of 93 forensic autopsy cases were analyzed. Deaths were classified into three major groups based on the scene, cause of death, and autopsy findings (external foam, frothy fluid in airways, overlapping medial edges of the lungs): (a) drowning in seawater (n = 35), (b) other asphyxia (n = 33), such as hangings (n = 23), suffocations (n = 6), and strangulation (n = 4), and (c) other causes (n = 25), such as multiple suffocations. Oxidative stress markers (MDA and GSH) and the immunohistochemical expression of SP-A were determined in both lungs. RESULTS: MDA levels were statistically higher in both lungs in cases of SWD than in other causes of death (p = 0.023). Similarly, significantly higher levels of GSH were observed in SWD compared to the rest of the deaths (p = 0.002), which was more significant in the right lung. Higher immunohistochemical expression of SP-A was obtained in the cases of SWD than in the other causes of death, with higher levels in both lungs. The correlation analysis between the levels of oxidative stress (MDA and GSH) in the lung tissue and the expression level of SP-A showed positive and significant results in SWD, both in the alveolar membrane and the alveolar space. CONCLUSIONS: Determining the levels of MDA and GSH in lung tissue and the expression level of SP-A can be of great importance in diagnosing SWD and the circumstances of death. A better understanding of the physiology of submersion is essential for its possible repercussions in adopting measures in the approach to patients who have survived a submersion process. It is also necessary for forensic pathology to correctly interpret the events that lead to submersion.

Dental Age Estimation Using Multiphoton Microscopy: A Potential Tool for Forensic Science.

Normal aging affects the different structures of teeth, in particular, the dentine. These changes are useful in forensic disciplines as a tool for age estimation. Although multiphoton (MP) microscopy has been used to explore dental pieces, a relationship between age and MP response of the human dentine has not been proposed yet. The relationship between MP signals and natural dentine aging is investigated herein. An index of age (INAG) combining two-photon excitation fluorescence (TPEF) and second harmonic generation (SHG) images has been used to quantify these changes. The results show that the INAG significantly decreases with age. Moreover, peritubular dentine size and collagen internal properties are also modified with age. This information confirms the usefulness of this technique in forensic age estimation after disasters (natural or manmade) with a lack of comprehensive fingerprint database. Courts and other government authorities might also benefit from this tool when the official age of individuals under special circumstances is required for legal or medical reasons.

Instruments to measure skills and knowledge of physicians and medical students in palliative care: A systematic review of psychometric properties.

PURPOSE: Palliative care is constantly increasing around the world. The knowledge and skills of future physicians in this area are crucial. This study evaluates the psychometric properties of knowledge and skills questionnaires used in palliative care, validated by physicians or medical students based on the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) methodology. METHODS: A systematic review was carried out in Cosmin Databases, Cochrane Library, PsycINFO, SciELO, Cinahl, and Medline up to September 2020 (updated June 2021), based on the COSMIN methodology and PRISMA recommendations. The psychometric properties of each included questionnaire were identified. Methodological quality, quality of results, and quality of evidence were evaluated. RESULTS: The search strategy yielded 12 questionnaires assessing the knowledge and skills of physicians or medical students. The Palliative Care Knowledge Questionnaire for PEACE (PEACE-Q) and Palliative Care Knowledge Test (PCKT) were the instruments with the highest scores for methodological quality, quality of results, and quality of evidence-based on the COSMIN methodology. CONCLUSIONS: PEACE-Q and PCKT should be the preferred choice to assess palliative care knowledge and skills in physicians. In-depth studies following COSMIN validation criteria are recommended to improve the psychometric properties and cross-cultural validation of the questionnaires.

Palliative care knowledge test for nurses and physicians: validation and cross-cultural adaptation.

BACKGROUND: Palliative care knowledge is essential in primary healthcare due to the increasing number of patients who require attention in the final stage of their life. Health professionals (physicians and nurses) need to acquire specific knowledge and abilities to provide high-quality palliative care. The development of education programmes in palliative care is necessary. The Palliative Care Knowledge Test (PCKT) is a questionnaire that evaluates the basic knowledge about palliative care, but it has not been adapted into Spanish, and its effectiveness and utility for Spanish culture have not been analysed. OBJECTIVE: The aim of this study was to report the translation into Spanish and a psychometric analysis of the PCKT. METHODS: The questionnaire survey was validated with a group of 561 physicians and nurses. The PCKT Spanish Version (PCKT-SV) was obtained from a process, including translation, back translation and revision by experts and a pilot study. The content validity and reliability of the questionnaire were analysed. RESULTS: The results showed internal consistency and reliability indexes similar to those obtained by the original version of PCKT. CONCLUSION: The PCKT-SV is a useful instrument for measuring Spanish-speaking physician and nurse knowledge of palliative care, and it is suitable to evaluate the effectiveness of training activities in palliative care.

Is There a Role for the Microbiome and Sudden Death? A Systematic Review.

BACKGROUND: Sudden unexpected death (SUD) is one of the most important and worthy investigation case profiles in emergency medicine and forensic pathology. Sudden unexpected deaths in adults (SUDA) are frequently caused by cardiac events, while infections usually cause those in infants younger than one year (SUDI), and to a lesser extent, in children older than one year (SUDC). However, in some instances of children under the age of one dying (SIDS), a cause is not discovered despite a thorough investigation that includes a review of clinical history, examination of the death scene, and a complete autopsy. Several studies demonstrate that the microbiome influences host immunity, alters susceptibility to viral respiratory infections, and has a vital role in various health, disease, and death outcomes. The main objective of this systematic review was to compile and offer a complete vision of the main lines of research on microbiome and sudden death that have emerged in recent years and their relationship with forensic sciences, as well as the possible contributions or limitations in the field of forensic sciences. METHODS: Following PRISMA principles, a systematic evaluation of the microbiome and sudden death in forensic science was conducted. In this review, our study classified the sudden deaths as SUDA, SUDI, and SIDS. RESULTS: The role of microbiome research in sudden death is discussed in this review. Various studies have linked the detection of different bacteria or viruses as a probable cause of sudden death. Bacteria analysed differ between studies that used autopsy specimens from deaths classified as SUDA, SUDI, and SIDS, or, except in the case of Staphylococcus aureus and Escherichia coli, which have been analysed in both SUDI and SIDS autopsies. In the case of viruses, only Cytomegalovirus has been analysed in both SIDS and SUDI cases. However, all the viruses studied are respiratory viruses found in samples of nasopharyngeal or lung fluid. CONCLUSIONS: Although the application of the microbiome in sudden death and other fields of forensic science is still in its early stages, a role of the microbiome in sudden deaths cannot be ruled out, but we cannot conclude that it is a significant factor either.

Trace elements in forensic human lung: A new approach to the diagnosis of seawater drowning. A preliminary study.

The diagnosing of drowning remains one of the most challenging activities for the forensic pathologist. There is little information on the impact on the lung as a target organ in death by drowning. We aimed to investigate the concentration of trace elements in the lungs of people who had suffered different types of death to evaluate the discriminating ability of trace elements to identify seawater drowning (SWD). A total of 11 trace elements were analyzed by Inductively Coupled Plasma-Mass Spectrometry in 74 forensic cases. Sampler scanning electron microscopy and Energy Dispersive X-ray spectroscopy (EDX) were used to identify ultrastructural lung alterations. A Principal Component Analysis (PCA) of trace elements was carried out. The trace elements in SWD lungs were detected in the following order of concentration: Br˃Zn˃Sr˃Cr˃Cu˃As˃Pb˃Se˃Mn˃Ni˃Cd. Our results showed significantly higher concentrations of Br and Sr (P = 0.010 and P = 0.000) and significantly lower concentrations of Zn, Pb, Cu, Cd, and Se in SWD compared with other causes of death. After adjusting by confounder factors, Sr and Br remained as predictive independent factors for diagnosis of drowning (p = 0.042, in both cases). These results were confirmed by PCA, which revealed a wide separation between SWD and the rest of the causes of death. Our SWD cohort was characterized by high concentrations of the trace elements Br and Sr and low concentrations of Zn, Pb, Cu, Cd, and Se in lung tissue, while PCA showed its discriminatory capacity to identify death by seawater drowning. These findings, together with those obtained using other techniques, can be of great importance in the diagnosis of SWD.

Diagnostic Application of Postmortem Cardiac Troponin I Pericardial Fluid/Serum Ratio in Sudden Cardiac Death.

In approximately 5% of unexpected deaths, establishing a conclusive diagnosis exclusively on the basis of anatomo-pathological findings in a classic autopsy is difficult. Postmortem biomarkers have been actively investigated as complementary indicators to help to reach valid conclusions about the circumstances of death. Several studies propose either the pericardial fluid or peripheral veins as a location for troponin determination, but the optimum sampling site is still a matter of debate. Our objective was to evaluate the association between the ratio of troponin values in the pericardial fluid and serum (determined postmortem) and the diagnosis of acute myocardial infarction (AMI) in the context of sudden cardiac death. We included 175 forensic cases. Two groups were established: AMI deaths (48; 27.4%) and the control group (127; 72.6%). The cardiac Troponin I (cTnI) values in the pericardial fluid and the troponin ratio were found to be associated with the cause of death. Univariate regression analyses showed that both age and the cTnI ratio were significantly associated with the diagnosis of AMI death. In a multivariate analysis, adjusting for confounding factors, the age and cTnI ratio were independent predictors of death from myocardial infarction. We performed a receiver operating characteristic (ROC) curve for the cTnI ratio for AMI death and selected a cut-off point. Our biomarker was found to be a valuable and highly effective tool for use in the forensic field as a complementary method to facilitate diagnosis in nonconclusive autopsies.

Elder abuse among Spanish and Iranian people: new methodological approach to the same old story.

Elder abuse continues to be a taboo, mostly underestimated, ignored by societies across the world. Recent systematic reviews and meta-analyses have revealed significant variations in the prevalence of elder abuse, with large geographic variations. This is the first study that compares the prevalence of elder abuse and risk factors between a European and Asian countries and using the same method. Cross-sectional surveys were conducted in Spain and Iran. Eight hundred forty subjects, aged 65 and over, were chosen randomly from patients in primary care health centres. Prevalence of abuse and subtypes and risk factors were obtained using structured interviews. To minimize the potential effects of selection bias, a propensity score matching was performed. Multiple correspondence analysis was used to evaluate the possible relationships among all the variables and to identify specific profiles. Five hundred thirty-two older people remained for the analysis after matching. The prevalence of abuse was 39.1% in Spain and 80.5% in Iran. Elder abuse and its subtypes are significantly more probable in Iran than in Spain. Out of every five elderly people questioned, two in Spain and four in Iran responded affirmatively to a question concerning elder abuse. Multiple correspondence analysis allows the differences between patterns of elder abuse between both populations to be visualized. Elder abuse is a prevalent problem in Spain and Iran. While some characteristics are shared in the pattern of abuse there are different profiles between the two countries. Detecting elder abuse should be a priority objective in clinical and forensic setting. Key points • This is the first study that compares the prevalence of elder abuse between a European and Asian country, using the same methodology. • Multiple correspondence analysis allows specific elder abuse profiles to be identified. • Elder abuse is significantly more likely to occur in Iran than in Spain. • Out of every five elderly people questioned, two in Spain and four in Iran responded affirmatively to a question concerning elder abuse.

Correlates of preferring a passive role in decision-making among patients with schizophrenia or bipolar disorder.

OBJECTIVE: To assess the factors associated with the persistence of clinician-led style in the therapeutic relationship in cases of serious mental illness, and the conditioning factors that the patients identify as determinants of their health. METHOD: Assessment of preferences in the decision-making process and health-related control locus of 107 outpatients with DSM-5 diagnosis of schizophrenia or bipolar disorder. Demographic and clinical information was also obtained through review of available records and using several scales. RESULTS: 64.4 % patients preferred to adopt a passive role in the therapeutic relationship. In the multivariate analysis, the preference of playing a passive role in the decision-making process was significantly associated with the elderly, being disabled, or the view that one's health depends on doctors (AUC ROC value: 0.80). CONCLUSIONS: Patients with severe mental illness more frequently preferred a passive role in the decision-making process. We found several factors associated with a preference for the "expert role" model. PRACTICE IMPLICATIONS: The identified factors may permit care to be tailored to the most probable expectations as regard decision-making. Since the populations concerned may be vulnerable and suffer inequalities in the provision of health services, promoting participation in the care process could help improve clinical parameters ethically.

Age and education as factors associated with medication literacy: a community pharmacy perspective.

BACKGROUND: Aging implies a higher prevalence of chronic pathologies and a corresponding increase in medication. The correct adherence and use of the medication are prerequisites for reducing risks of disease progression, comorbidity, and mortality. Medication literacy (ML) is the specific ability to safely access and understand the information available concerning medication, and to act accordingly. Currently, there are few specific instruments that ascertain the extent of ML in the general population. The aim of this work was to analyse ML in a large cohort of pharmacy customers. METHODS: A total of 400 community pharmacy clients were analyzed to assess the level of ML (documental and numeracy) through the validated MedLitRxSE tool. RESULTS: The results showed that out of a total of 400 community pharmacy clients only 136 (34%) had an adequate degree of ML, while the rest of the clients (n = 264; 66%) were adjudged not to have this ability. Statistically significant differences were found between the different age groups in terms of ML (P < 0.001; OR = 0.312; 95% CI: 0.195-0.499), the 51-65 and >65-year age groups having a lower frequency of adequate ML (23.5 and 7.1%, respectively) than the rest of the age groups. A statistically significant increase in adequate ML was observed as the academic level of the clients increased (P < 0.001; OR = 15.403; 95% CI: 8.109-29.257). Multivariate logistic regression confirmed the influence of both variables on ML. CONCLUSIONS: An inadequate ML level was found in community pharmacy clients over the age of 51, and also in those with primary or non-formal studies. Our data add to our knowledge about ML, and should pharmacists and other health professionals to adopt new strategies to prevent, or at least reduce, errors in taking medicines, thus avoiding the undesirable effects of any misuse.

Proteomics in Deaths by Drowning: Diagnostic Efficacy of Apolipoprotein A1 and α-1Antitrypsin, Pilot Study.

Drowning is one of the leading causes of death worldwide. The pathophysiology of drowning is complex and, sometimes, interpretation of the circumstances of death in the autopsy becomes the main source of information in its diagnosis. New advances in medical research, such as proteomics, especially in forensic pathology, are still in the development. We proposed to investigate the application of Mass Spectrometry-based technologies, to identify differentially expressed proteins that may act as potential biomarkers in the postmortem diagnosis of drowning. We performed a pilot proteomic experiment with the inclusion of two drowned and two control forensic cases. After applying restrictive parameters, we identified apolipoprotein A1 (ApoA1) and α-1 antitrypsin as differentially expressed between the two diagnostic groups. A validation experiment, with the determination of both proteins in 25 forensic cases (16 drowned and 9 controls) was performed, and we corroborated ApoA1 higher values in the drowning group, whereas α-1 antitrypsin showed lower levels. After adjusting by confounder factors, both remained as predictive independent factors for diagnosis of drowning (p = 0.010 and p = 0.022, respectively). We constructed ROC curves for biomarkers' levels attending at the origin of death and established an ApoA1 cut-off point of 100 mg/dL. Correct classification based on the diagnosis criteria was reached for 73.9% of the cases in a discriminant analysis. We propose apolipoprotein A1 (with our cutoff value for correct classification) and α-1 antitrypsin as valuable biomarkers of drowning. Our study, based on forensic cases, reveals our proteomic approach as a new complementary tool in the forensic diagnosis of drowning and, perhaps, in clinical future implications in drowned patients. However, this is a pilot approach, and future studies are necessary to consolidate our promising preliminary data.

Impact of the Human Microbiome in Forensic Sciences: a Systematic Review.

Numerous studies relate differences in microbial communities to human health and disease; however, little is known about microbial changes that occur postmortem or the possible applications of microbiome analysis in the field of forensic science. The aim of this review was to study the microbiome and its applications in forensic sciences and to determine the main lines of investigation that are emerging, as well as its possible contributions to the forensic field. A systematic review of the human microbiome in relation to forensic science was carried out by following PRISMA guidelines. This study sheds light on the role of microbiome research in the postmortem interval during the process of decomposition, identifying death caused by drowning or sudden death, locating the geographical location of death, establishing a connection between the human microbiome and personal items, sexual contact, and the identification of individuals. Actinomycetaceae, Bacteroidaceae, Alcaligenaceae, and Bacilli play an important role in determining the postmortem interval. Aeromonas can be used to determine the cause of death, and Corynebacterium or Helicobacter pylori can be used to ascertain personal identity or geographical location. Several studies point to a promising future for microbiome analysis in the different fields of forensic science, opening up an important new area of research.

Aging and trace elements in human coronal tooth dentine.

Teeth are a fundamental tool in forensic odontology for identification in a legal context of those individuals who cannot be identified visually or by other means. Dentine presents physiological exchanges of in trace elements after a period of mineralization and several factors can affect its concentration. The aim of this study was to investigate the concentration of 25 trace elements in the coronal dentine according to sex and type of tooth to determine their relationship with age. A total of 25 trace elements were analyzed in 150 human coronal dentine. Teeth were classified into three age groups, sex and tooth type. The trace elements were grouped as potentially toxic or essential. Inductively Coupled Plasma-Mass Spectrometry and Atomic Emission Spectroscopy were used. The toxic and essential elements were detected in the following order of concentration: Al > Pb > Sn > Li > As > Cd and Ca > P > Mg > Na > S > K > Sr > Zn > Ba > Fe > B > Ti > Mn > Cr > Ni > Cu > Co > Se > V. Our findings show an increase in the concentration of toxic (Pb, Li and Sn) and essential (B, Ba, K, Sr, S and Mg) elements in coronal dentin related to the age of the teeth, regardless of sex. The concentrations of Pb and K in dentin of molars and premolars are the elements that best relate their variations with age. In view of our results, the analysis of these trace elements in dentin in combination with other types of techniques could be established as an element to consider in age dating studies in different forensic situations.

Compulsory admissions and preferences in decision-making in patients with psychotic and bipolar disorders.

PURPOSE: Participation in medical decisions and taking into account patients' values and preferences are especially important for psychiatric patients who may be treated against their will. The increasing rates of coercive measures and the underlying clinical, ethical, and legal issues highlight the need to examine their use in psychiatry. Although limited congruence in decision-making preferences may be on the basis of these coercive practices, this issue has not been adequately addressed. We explore the relationship between compulsory admissions and congruence in decision-making preferences in mental health settings. METHODS: Cross-sectional study among 107 outpatients with DSM diagnoses of schizophrenia of bipolar disorder using the Control Preference Scale to assess congruence in decision-making experienced and preferred style. History of compulsory admissions was obtained through review of available records. Descriptive statistics and multivariate analyses were used. RESULTS: 70% of patients reported experiencing their preferred style of decision-making and 44% patients had history of compulsory admissions. These patients were more autonomous and preferred to take a more active role. The degree of congruence was lower in patients with previous compulsory admissions. The best predictors of compulsory admissions were not having a regular doctor and the unmatched participation preferences. CONCLUSIONS: Patients who experienced a different level of participation in decision-making than desired more frequently had compulsory admissions. We propose to assess participation preferences each time a relevant treatment decision is about to be made and tailor care accordingly. We identified several factors leading to compulsory admissions that can be modified to prevent further coercive measures.

Association between protein profile and postmortem interval in human bone remains.

Proteomic techniques in bones forensic samples are increasingly, being applied. The main aim of forensic sciences is the estimation of postmortem interval. Most current techniques are useful for the first post-mortem stages. However, in the case of osseous remains, these techniques may be difficult to use due to the high level of decomposition of the sample. Our objective was to attempt to know whether there is a protein profile in human bone remains that would enable a late postmortem. interval ranging from 5 to 20 years postmortem to be estimated. A total of 40 femur bones from 40 different cadavers (data range 5-20 years) were use. Of the 275 total proteins, we excluded the circulating ones (n = 227), leaving a total of 48 proteins (29 structural and 19 functional) were found. A multiple correspondence analysis was applied on the 48 proteins. Finally selecting 32 proteins that allowed us to discriminate between the. two groups of postmortem interval. Analysis of the protein profile present in bone permits an approximation of the date of death within the studied interval, and could be used to complement other tests for estimating the postmortem interval.

Assessment of Motivations and Willingness to Participate in Research of Outpatients With Anxiety, Mood, and Psychotic Disorders.

The motivations of participants recruited for research, especially from potentially vulnerable populations, have received increasing attention. The present investigation compares the motivations and willingness to participate in research of 134 psychiatric outpatients and 50 controls. The willingness to participate of both groups was similar. We found a higher proportion of psychiatric admissions and a higher degree of computer literacy among those willing to participate. Regardless of their decision concerning participation, the reasons given by the members of both groups were logical and concordant with the related literature. This suggests that negative views about the motivations of psychiatric patients to act as research participants are unfounded. Efforts should focus on the predictors of willingness to participate that we have identified for improving recruitment. The implications of these results for research are discussed.

Perceptions of health professionals about the quality of communication and deliberation with the patient and its impact on the health decision making process.

The information process is considered a core element in decision- making and an obligatory matter of concern for the health professional. Rather than information per se, we should perhaps mention the need for communication between the health professional and the patient, which should be appropriate to each specific case and situation. Interaction and communication during the relationship generates a degree of trust that contributes to improving care quality and health-related results. The aim of this study is to know the perception of professionals on the quality of communication and its impact on the decision-making process of the patient and the degree of involvement of health professionals in the process of communication with the patient. A sample of 2186 health professionals (1578 nurses, 586 physicians, and 22 pharmacists) was studied. A questionnaire composed of 20 items dealing with the process of communication with the patient and obtaining informed consent was administered. Our study revealed the high consideration that professionals hold of their communication skills with patients since almost 80% of those surveyed, think they are sufficiently skilled in this area. Professionals refers that nurses are most skilled at communicating with patients. Communication in the clinical relationship must not only serve as a way for the professional to obtain information from the patient on their pathology, but also as a means to inform patients so that they understand their illness. Patients also like to feel that they are being listened to and are co-participants in the care process. Communication should be a continuous object of study for all health professionals, both in primary and specialised attention.

Quantification of nitrogenous bases, DNA and Collagen type I for the estimation of the postmortem interval in bone remains.

Estimating the postmortem interval (PMI) is an important goal in forensic medicine and continues to be one of the most difficult tasks of the forensic investigator. Few accurate methods exist to determine the time since death of skeletonized human remains due to the great number of intrinsic and external factors that may alter the normal course of postmortem change. The purpose of this research was to assess the usefulness of various biochemical parameters, such as nitrogenous bases (adenine, guanine, purines, cytosine, thymine, pyrimidines, hypoxanthine and xanthine), DNA and Collagen Type I peptides to estimate PMI. These parameters were analysed in cortical bone for the establishment of data in a total of 80 long bones of 80 corpses (50 males, 30 females) with a mean age of 68.31 years (S.D.=18.021, range=20-97). The bones were removed from the cement niches of a cemetery in Murcia (south-eastern Spain), where they had lain for between 5 and 47 years (mean time 23.83 years, S.D.=10.85). Our results show a significant decrease in adenine (p=0.0004), guanine (p=0.0001), purines (p=0.0001), cytosine (p=0.0001), thymine (p=0.0226), pyrimidines (p=0.0002) and the number of peptides of Collagen type I (p=0.0053) in those with a PMI≥20 years. In a curvilinear regression analysis the results show that 30.6% of the variable PMI could be explained by guanine concentration, in bones with a PMI<20 years, while in cases of a PMI≥20 years, the variable that best explained membership of this group was adenine (38.0%). In the discriminant analysis applied to the all the variables as a function of PMI when two groups were established, 86.7% of the cases were correctly classified. These results show that the quantification of Collagen type I proteins and nitrogenous bases could be used as a complementary tool, together with other analyses, in the estimation of PMI.